Analysis of Risk Factors for Pediatric Respiratory Syncytial Virus Pneumonia and Optimization of Vaccination Strategies

Analysis of Risk Factors for Pediatric Respiratory Syncytial Virus Pneumonia and Optimization of Vaccination Strategies | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Analysis of Risk Factors for Pediatric Respiratory Syncytial Virus Pneumonia and Optimization of Vaccination Strategies Zhiyuan Zhong, Mengyuan He, Xiaoyu Li, Wenqi Yu, Su Liu, Ran Yao, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7850182/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 7 You are reading this latest preprint version Abstract Objective The study focuses on pneumonia in children caused by respiratory syncytial virus (RSV), which is linked to high morbidity, hospitalization, and mortality rates. It aims to enhance pediatric vaccination strategies by examining the clinical differences between severe and non-severe RSV pneumonia cases. Methods Conducted from April 2023 to August 2025, this retrospective study used electronic medical records from the Pediatric Medical Center at The Seventh Affiliated Hospital of Sun Yat-sen University. We analyzed 387 hospitalized children with RSV, assessing risk factors through univariate and multivariate logistic regression. Results Based on the inclusion and exclusion criteria, 350 patients were included in the final analysis. Among these, 157 patients (44.9%) were diagnosed with severe respiratory syncytial virus pneumonia (SRSVP), while 193 patients (55.1%) were diagnosed with non-severe respiratory syncytial virus pneumonia (NRSVP). Through multivariate logistic regression analysis, the presence of siblings and low body weight were identified as significant risk factors for the development of SRSVP(Having siblings: odds ratio 1.568, 95% CI 1.015–2.421, P = 0.043; Weight: odds ratio 0.939, 95% CI 0887,0.995, P = 0.032). Conclusion The study concludes that the risk of developing severe respiratory syncytial virus pneumonia (SRSVP) is significantly associated with specific epidemiological characteristics of the patient. Notably, having siblings and low body weight emerged as independent predictors for the onset of SRSVP. Respiratory syncytial virus pneumonia Severe Vaccination Predictors Children Figures Figure 1 Background Respiratory syncytial virus (RSV) is the predominant etiological agent responsible for acute lower respiratory tract infections (LRTIs) in infants and young children, and it constitutes a major cause of hospitalization due to pneumonia and other LRTIs within this demographic [ 1 , 2 ]. On a global scale, RSV is implicated in an estimated 33 million instances of acute LRTI among children aged 0 to 60 months, contributing to 2.0% of mortalities within this age group. Importantly, over 95% of RSV-related LRTI cases and more than 97% of RSV-associated deaths occur in low- and middle-income countries (LMICs) [ 3 – 5 ]. Currently, the management of RSV infection predominantly involves supportive care, as specific antiviral therapies are not yet available. Severe RSV infections place a substantial burden on healthcare systems and economies [ 6 , 7 ]. Consequently, the development of effective prevention and treatment strategies is imperative. Presently, the primary preventive measure against RSV infection is the use of monoclonal antibodies (mAbs) [ 8 ]. Although several RSV mAbs are undergoing clinical development, their widespread adoption has been hindered by high costs, the necessity for monthly administration, and restrictive eligibility criteria [ 9 , 10 ]. Therefore, it is crucial to analyze the risk factors associated with severe versus non-severe RSV infection to identify target populations for vaccination. Numerous studies have demonstrated that independent risk factors for respiratory syncytial virus (RSV) infection are significantly correlated with younger age, premature birth, and the presence of comorbidities, particularly cardiovascular and pulmonary diseases, as well as certain genetic disorders [ 11 , 12 ]. Additionally, other underlying medical conditions that may heighten the risk of young children progressing from mild to severe illness and increase mortality rates require further investigation [ 7 , 13 – 15 ]. In light of this, our study examines the clinical data of patients with RSV pneumonia to identify risk factors contributing to the development of severe RSV pneumonia (SRSVP) and to explore their potential implications for vaccination strategies. Methods Study Subjects We conducted a retrospective cohort study of patients treated for RSV infection at The Seventh Affiliated Hospital of Sun Yat-sen University, collecting medical record data for all patients diagnosed with RSV infection between April 2023 and August 2025. The Institutional Review Board of the Seventh Affiliated Hospital of Sun Yat-sen University approved this study and waived informed consent due to its retrospective design and the use of deidentified data. This study adhered strictly to the principles of the 1964 Declaration of Helsinki and its subsequent amendments and was approved by the Medical Ethics Committee of The Seventh Affiliated Hospital of Sun Yat-sen University (Approval No.: KY-2024-312-01). Given the non-interventional and retrospective nature of the study, the ethics committee waived the requirement for written informed consent from patients and their legal guardians. Inclusion criteria were:1.(1) diagnosis of SRSVP according to the Guidelines for the Diagnosis, Treatment, and Prevention of Respiratory Syncytial Virus Infection in Children (2024 Edition) [ 16 ] and the Guidelines for the Management of Community-Acquired Pneumonia in Children (2024 Revision) [ 17 ]. (2) age under 18 years. Exclusion criteria were: age over 18 years, leaving the hospital against medical advice, and underlying conditions such as severe malnutrition, chronic heart disease, congenital diseases, immunodeficiency, malignant tumors, or multiple traumas. Variables and Outcome Measurement We collected patient case data from the pediatric inpatient records of The Seventh Affiliated Hospital of Sun Yat-sen University to obtain baseline characteristics of eligible patients. This included information on age, sex, weight, height, season of onset, preterm birth, history of wheezing, eczema, history of allergies, and whether the patient had siblings, as detailed in Fig. 1 . Statistical Analysis Data analysis was performed using IBM SPSS Statistics (Version 25.0; IBM Corporation, Armonk, NY, USA). Descriptive statistics were presented as mean ± standard deviation (SD), median (interquartile range), or counts and percentages, depending on the data type. Continuous variables were expressed as mean ± SD or median (interquartile range) and compared using paired t-tests or Wilcoxon rank-sum tests. Categorical variables were reported as counts and percentages and compared using the chi-square test. To identify risk factors associated with RSV infection, we constructed a multivariate logistic regression model, calculating odds ratios (OR) and their corresponding 95% confidence intervals (CI), with statistical significance set at p < 0.05. Due to multicollinearity among age, height, and weight, we conducted two separate regression analyses. The multivariate regression model was built using baseline variables that were clinically significant or had a P-value < 0.2 in the univariate analysis. The selected variables were carefully screened to ensure the interpretability of the final model. Additionally, we constructed a Receiver Operating Characteristic (ROC) curve to predict indicators of respiratory failure. Results Between April 2023 and August 2025, a total of 387 patients hospitalized for RSV infection were admitted to the Children's Medical Center of the Seventh Affiliated Hospital of Sun Yat-sen University. Of these, 350 patients met the diagnostic criteria for RSV pneumonia. During the initial screening process, 37 patients (9.6%) were excluded because they did not meet the study inclusion criteria. The reasons for exclusion were as follows: 19 patients were diagnosed with upper respiratory tract infection, 5 patients discharged without medical advice, 1 patient had severe protein malnutrition, 9 patients had malignancies, 1 patient was admitted for multiple trauma, and 2 patients were adults. The final 350 patients were included in the analysis, of whom 157 (44.9%) were diagnosed with SRSVP and 193 (55.1%) with nonsevere RSV pneumonia (NRSVP) (see Fig. 1 ). General information of SRSVP and NRSVP groups In this study, we conducted a detailed analysis of the basic characteristics of 193 patients with NRSVP and 157 patients with SRSVP. The results showed that the mean age, weight, and height of NRSVP patients were 1 year, 10 kg, and 76 cm, respectively; whereas the mean age, weight, and height of SRSVP patients were 0.8 years, 9.6 kg, and 74 cm, respectively. Statistical analysis revealed statistically significant differences in age, weight, and height between the two groups (P < 0.05), with the SRSVP group showing lower age, weight, and height than the NRSVP group. Furthermore, the SRSVP group had a higher proportion of patients with siblings (51.6% vs. 39.4%, P < 0.05), potentially suggesting that family environment has a role in disease severity. Regarding other clinical characteristics, no significant differences were found between the two groups in body mass index, sex, season of onset, birth during epidemic season, history of prematurity, history of wheezing, or history of eczema (P > 0.05). This suggests that these factors may not be the primary factors affecting the severity of RSV pneumonia. These results provide important clues for further exploring the potential factors affecting the severity of RSV pneumonia. Detailed data are shown in Table 1 . Table 1 Participation characteristics Characteristics Non-severe (n = 193) Severe (n = 157) P Age (years) 1.0(0.6, 2.2) 0.8(0.4, 2.1) 0.003 Weight (kg) 10.0(8.0,13.0) 9.6(7.5,12.0) 0.026 Height (cm) 76.0(70.0,90.0) 74.0(66.0,87.0) 0.002 BMI 16.4(15.3,17.6) 16.4(15.2,18.4) 0.478 Born in epidemic season 80(41.5%) 74(47.1%) 0.287 Season of onset / / / Spring 54(28.0%) 44(28.0%) 0.844 Summer 108(56.0%) 86(54.8%) / Autumn 21(10.9%) 21(13.4%) / Winter 10(5.2%) 6(3.8%) / Male 121(62.7%) 96(61.1%) 0.767 Female 72(37.3%) 61(38.9%) / Preterm birth 14(7.3%) 19(12.1%) 0.123 History of wheezing 11(5.7%) 14(8.9%) 0.245 History of eczema 7(3.6%) 6(3.8%) 0.924 History of allergy 18(9.3%) 8(5.1%) 0.133 Having siblings 76(39.4%) 81(51.6%) 0.022 Logistic Multivariate Regression Analysis Between SRSVP and NRSVP Groups Based on the results of the univariate analysis, we conducted a further logistic multivariate regression analysis to identify independent risk factors for severe respiratory syncytial virus pneumonia(Having siblings: odds ratio 1.568, 95% CI 1.015–2.421, P = 0.043; Weight: odds ratio 0.939, 95% CI 0887,0.995, P = 0.032;Model:Logit(P) = 0.45 × Having siblings + 0.627 × History of wheezing − 0.156 × History of eczema − 0.0516 × History of allergy + 0.436 × Preterm birth − 0.063 × Weight + 0.192). The results showed that having siblings and lower body weight were independent risk factors for SRSVP. Detailed data are shown in Table 2 . Table 2 Multivariate analysis between SRSVP and NRSVP groups Characteristic B Std. Error Wald df Sig. Exp (B) 95% C.I. for EXP (B) Having siblings 0.450 0.222 4.110 1 0.043 1.568 1.015, 2.421 History of wheezing 0.627 0.438 2.046 1 0.153 1.871 0.793, 4.415 History of eczema -0.156 0.590 0.070 1 0.791 0.856 0.269, 2.718 History of allergy -0.0516 0.467 1.218 1 0.270 0.597 0.239, 1.492 Preterm birth 0.436 0.380 1.316 1 0.251 1.547 0.734, 3.261 Weight -0.063 0.029 4.578 1 0.032 0.939 0.887, 0.995 Constant 0.192 0.341 0.317 1 0.573 1.212 Discussion This study investigated 387 children hospitalized for RSV-related acute respiratory infections at the Pediatric Medical Center of The Seventh Affiliated Hospital of Sun Yat-sen University during the 2023–2025 respiratory virus season. Among them, 157 children were diagnosed with severe disease, 193 with non-severe disease, and 37 were excluded for not meeting the inclusion criteria. Severe cases were observed across all age groups, including previously healthy children and those with chronic conditions. The study found that risk factors for severe disease included having siblings (P = 0.043) and low body weight (P = 0.032). These results reveal the evolving clinical factors of pediatric RSV infection based on current epidemiological characteristics, suggesting that such patients are more suitable candidates for vaccination. Our study found that the median weight of patients in the SRSVP group was lower than that of the NRSVP group (9.6 kg vs. 10.0 kg). Additionally, a higher proportion of patients in the SRSVP group had siblings. Previous research has indicated that low body weight is a major risk factor for severe RSV disease in children, and infants hospitalized with RSV-related illness are at high risk for requiring intensive care and longer hospital stays [ 18 – 20 ]. Similarly, having siblings is a significant predictor of disease severity, especially having older siblings, possibly because older children are more likely to introduce RSV into the household [ 21 – 23 ]. Our research further suggests that vaccination strategies should prioritize children with lower body weight and those with siblings. In previous studies, age and a history of preterm birth have been considered major risk factors for severe RSV infection [ 24 – 26 ]. However, in our study, age and preterm birth did not show significant differences in the univariate analysis. This does not negate their role as risk factors but may be attributed to the widespread adoption of proactive preventive measures for high-risk infants, such as preterm babies, in recent years, including the use of RSV immunoprophylaxis agents like palivizumab [ 27 , 28 ]. Our study cohort may have benefited from these interventions, which could have mitigated the inherent risk of severe disease associated with preterm birth, rendering it statistically non-significant in our analysis. Furthermore, the sample size might have been insufficient to detect smaller but genuine effect differences related to age or preterm birth. Nevertheless, the trends we observed are consistent with the general direction of previous literature: the proportion of preterm infants was slightly higher in the severe group than in the non-severe group (12.1% vs. 7.3%), and the severe group was younger (0.8 years vs. 1.0 year). Although these differences did not reach statistical significance, the trends are notable. The cost and cost-effectiveness of RSV-related products are critical factors in the decision-making processes of all countries. Product pricing varies by country, which decisively affects affordability and cost-effectiveness. Multiple studies have shown that, depending on the price and target population, both mAb and vaccine strategies can be cost-effective in high-income and low- and middle-income countries alike [ 29 – 32 ]. Our study suggests that vaccination or mAb administration should be prioritized for high-risk pediatric populations, such as patients with siblings or lower body weight, who are more likely to develop severe RSV infection. Prioritizing these children for vaccination in the next epidemic season could not only effectively prevent severe RSV infections but also significantly reduce medical expenditures for patients and productivity losses for caregivers. This study has several limitations that require consideration. First, due to its retrospective design, inherent biases are unavoidable. Second, this study included only hospitalized patients, which may limit the generalizability of the findings. Furthermore, we did not perform prospective, external, or internal validation of our model to more comprehensively explore the prevalence of RSV, which may affect the reliability of our results. Finally, the data in this study were obtained from a single center with a relatively small sample size, which limited our ability to adjust for multiple covariates and may affect the generalizability of our results. In future studies, we plan to include outpatients and validate these results using a more diverse dataset to improve the generalizability of our study. Conclusion Our analysis of clinical data from patients with RSV pneumonia indicates a significant association between the risk of developing SRSVP and the patient's epidemiological characteristics. Through multivariate logistic regression analysis, we identified the presence of siblings and lower body weight as independent predictors for the onset of SRSVP. Consequently, this study advocates for RSV prevention strategies that encompass all infants and young children, with a particular focus on those with siblings and lower body weight. These indicators offer clinicians a practical approach for the rapid identification of "ultra-high-risk" children. Prioritizing vaccination for these children is anticipated to confer the greatest health benefits. Declarations Ethical approval This study strictly adhered to the principles of the Declaration of Helsinki and received formal approval from the Ethics Committee of the Seventh Affiliated Hospital of Sun Yat-sen University before the study began. Given the use of de-identified secondary data and the fact that data collection was completed through a retrospective review of medical records, no informed consent was required. Instead, a waiver of informed consent was obtained from the Institutional Review Board of the Seventh Affiliated Hospital of Sun Yat-sen University, in accordance with relevant laws and regulations regarding the protection of participants' rights, welfare, and privacy. To ensure patient privacy, no sensitive personal information, such as names and medical record numbers, was included during data collection. Competing interests The authors declare that they have no conflicts ofinterest. Funding Nobody funding this research. Author Contribution Zhiyuan Zhong, Mengyuan he, Xiaoyu Li, Mengqi Yu, Ran Yao, Su Liu and Junfeng Xie contributed to the study conception and design. Material preparation, data collection and analysis were performed by Zhiyuan Zhong, Mengyuan He, Xiaoyu Li, Mengqi Yu. The first draft of the manuscript was written by Zhiyuan Zhong, Mengyuan he, Xiaoyu Li. Ran Yao, Su Liu and Junfeng commented on previous versions of the manuscript. Zhiyuan Zhong, Mengyuan he, Xiaoyu Li, Mengqi Yu, Ran Yao, Su Liu and Junfeng read and approved the final manuscript. Acknowledgements We would like to thank Prof. Feiqiu Wen and Prof. Chi-kong Li for their guidance on this thesis. Data Availability Mainly result-based data are available within the manuscript, for those who need full data and additional material related to the manuscript can be obtained from the Corresponding author with a reasonable formal request via email; [ [email protected] ](mailto: [email protected] ) References Xu H, Aparicio C, Wats A, Araujo BL, Pitzer VE, Warren JL, et al. Estimated Effectiveness of Nirsevimab Against Respiratory Syncytial Virus. JAMA Netw Open. 2018;8:e250380. https://doi.org/10.1001/jamanetworkopen.2025.0380 . Karron RA. Preventing respiratory syncytial virus (RSV) disease in children. Science. 2021;372:686–7. https://doi.org/10.1126/science.abf9571 . Li Y, Wang X, Blau DM, Caballero MT, Feikin DR, Gill CJ, et al. Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in children younger than 5 years in 2019: a systematic analysis. Lancet. 2022;399:2047–64. https://doi.org/10.1016/S0140-6736(22)00478-0 . Jefferies K, Drysdale SB, Robinson H, Clutterbuck EA, Blackwell L, McGinley J, et al. Presumed Risk Factors and Biomarkers for Severe Respiratory Syncytial Virus Disease and Related Sequelae: Protocol for an Observational Multicenter, Case-Control Study From the Respiratory Syncytial Virus Consortium in Europe (RESCEU). J Infect Dis. 2020;222 Supplement7:S658–65. https://doi.org/10.1093/infdis/jiaa239 . Geoghegan S, Erviti A, Caballero MT, Vallone F, Zanone SM, Losada JV, et al. Mortality due to Respiratory Syncytial Virus. Burden and Risk Factors. Am J Respir Crit Care Med. 2017;195:96–103. https://doi.org/10.1164/rccm.201603-0658OC . Roymans D, Alnajjar SS, Battles MB, Sitthicharoenchai P, Furmanova-Hollenstein P, Rigaux P, et al. Therapeutic efficacy of a respiratory syncytial virus fusion inhibitor. Nat Commun. 2014;8:167. https://doi.org/10.1038/s41467-017-00170-x . Snyder BM, Achten NB, Gebretsadik T, Wu P, Mitchel EF, Escobar G, et al. Personalized Infant Risk Prediction for Severe Respiratory Syncytial Virus Lower Respiratory Tract Infection Requiring Intensive Care Unit Admission. Open Forum Infect Dis. 2024;11:ofae077. https://doi.org/10.1093/ofid/ofae077 . Pecenka C, Sparrow E, Feikin DR, Srikantiah P, Darko DM, Karikari-Boateng E, et al. Respiratory syncytial virus vaccination and immunoprophylaxis: realising the potential for protection of young children. Lancet. 2024;404:1157–70. https://doi.org/10.1016/S0140-6736(24)01699-4 . Terstappen J, Hak SF, Bhan A, Bogaert D, Bont LJ, Buchholz UJ, et al. The respiratory syncytial virus vaccine and monoclonal antibody landscape: the road to global access. Lancet Infect Dis. 2024;24:e747–61. https://doi.org/10.1016/S1473-3099(24)00455-9 . Ishiwada N, Akaishi R, Kobayashi Y, Togo K, Yonemoto N, Matsuo M, et al. Cost-Effectiveness Analysis of Maternal Respiratory Syncytial Virus Vaccine in Protecting Infants from RSV Infection in Japan. Infect Dis Ther. 2024;13:1665–82. https://doi.org/10.1007/s40121-024-01000-6 . Ma H-Y, Lin I-F, Liu Y-C, Yen T-Y, Huang K-YA, Shih W-L, et al. Risk Factors for Severe Respiratory Syncytial Virus Infection in Hospitalized Children. Pediatr Infect Dis J. 2024;43:487–92. https://doi.org/10.1097/INF.0000000000004270 . Curns AT, Rha B, Lively JY, Sahni LC, Englund JA, Weinberg GA, et al. Respiratory Syncytial Virus-Associated Hospitalizations Among Children <5 Years Old: 2016 to 2020. Pediatrics. 2024;153:e2023062574. https://doi.org/10.1542/peds.2023-062574. Rao S, Armistead I, Messacar K, Alden NB, Schmoll E, Austin E, et al. Shifting Epidemiology and Severity of Respiratory Syncytial Virus in Children During the COVID-19 Pandemic. JAMA Pediatr. 2023;177:730. https://doi.org/10.1001/jamapediatrics.2023.1088 . Ma H-Y, Lin I-F, Liu Y-C, Yen T-Y, Huang K-YA, Shih W-L, et al. Risk Factors for Severe Respiratory Syncytial Virus Infection in Hospitalized Children. Pediatr Infect Disease J. 2024;43:487–92. https://doi.org/10.1097/INF.0000000000004270 . Sudnik P, Walsh EE, Branche AR, Islam MR, Falsey AR. Comprehensive Analysis of Cardiovascular Events and Risk Factors in Patients Hospitalized With Respiratory Syncytial Virus. Clin Infect Dis. 2025;ciaf310. https://doi.org/10.1093/cid/ciaf310 . Guideline for the. diagnosis, treatment, and prevention of respiratory syncytial virus infection in children in China. Pediatr Invest. 2025;9:205–20. https://doi.org/10.1002/ped4.70010 . Subspecialty Group of Respiratory, the Society of Pediatrics, Chinese Medical Association, Board E, Chinese Journal of Pediatrics, China Medicine Education Association Committee on Pediatrics. [Guidelines for the management of community-acquired pneumonia in children (2024 revision)]. Zhonghua Er Ke Za Zhi. 2024;62:920–30. https://doi.org/10.3760/cma.j.cn112140-20240728-00523 . Wang Y, Xiang Y, Jin R, Li B, Feng X, Han Q, et al. Risk factors for severe lower respiratory tract infection among children under 5 years of age hospitalized with respiratory syncytial virus. Eur J Clin Microbiol Infect Dis. 2025;44:2239–51. https://doi.org/10.1007/s10096-025-05191-9 . Tielsch JM, Steinhoff M, Katz J, Englund JA, Kuypers J, Khatry SK, et al. Designs of two randomized, community-based trials to assess the impact of influenza immunization during pregnancy on respiratory illness among pregnant women and their infants and reproductive outcomes in rural Nepal. BMC Pregnancy Childbirth. 2015;15:40. https://doi.org/10.1186/s12884-015-0470-y . Tamir S, Golan-Tripto I, Hazan I, Adar A, Burrack N, Cohen B, et al. Does weight influence the course of RSV bronchiolitis in hospitalized infants? Eur J Pediatr. 2024;183:2663–9. https://doi.org/10.1007/s00431-024-05521-7 . Havdal LB, Bøås H, Bekkevold T, Bakken Kran A-M, Rojahn AE, Størdal K, et al. Risk factors associated with severe disease in respiratory syncytial virus infected children under 5 years of age. Front Pediatr. 2022;10:1004739. https://doi.org/10.3389/fped.2022.1004739 . Deng S, Cong B, Edgoose M, De Wit F, Nair H, Li Y. Risk factors for respiratory syncytial virus-associated acute lower respiratory infection in children under 5 years: An updated systematic review and meta-analysis. Int J Infect Dis. 2024;146:107125. https://doi.org/10.1016/j.ijid.2024.107125 . Zylbersztejn A, Pembrey L, Goldstein H, Berbers G, Schepp R, van der Klis F, et al. Respiratory syncytial virus in young children: community cohort study integrating serological surveys, questionnaire and electronic health records, Born in Bradford cohort, England, 2008 to 2013. Euro Surveill. 2021;26:2000023. https://doi.org/10.2807/1560-7917.ES.2021.26.6.2000023 . Papenburg J, Hamelin M-È, Ouhoummane N, Carbonneau J, Ouakki M, Raymond F, et al. Comparison of risk factors for human metapneumovirus and respiratory syncytial virus disease severity in young children. J Infect Dis. 2012;206:178–89. https://doi.org/10.1093/infdis/jis333 . Liu H-F, Wang Y-Y, Zhang X-Z, Li H-Y, Xiang M, Lu R, et al. Comparison of characteristics of children hospitalized for respiratory syncytial virus infection during the pre- and post-COVID-19 eras: a multicenter retrospective study. BMC Infect Dis. 2024;24:1009. https://doi.org/10.1186/s12879-024-09783-2 . Kobiałka M, Jackowska T, Wrotek A. Risk Factors for Severe Respiratory Syncytial Virus Infection in Hospitalized Children. Viruses. 2023;15:1713. https://doi.org/10.3390/v15081713 . Brady MT, Byington CL, Davies HD, Edwards KM, Jackson MA, Maldonado YA, et al. Updated guidance for palivizumab prophylaxis among infants and young children at increased risk of hospitalization for respiratory syncytial virus infection. Pediatrics. 2014;134:415–20. https://doi.org/10.1542/peds.2014-1665 . Griffin MP, Yuan Y, Takas T, Domachowske JB, Madhi SA, Manzoni P, et al. Single-Dose Nirsevimab for Prevention of RSV in Preterm Infants. N Engl J Med. 2020;383:415–25. https://doi.org/10.1056/NEJMoa1913556 . Hodgson D, Wilkins N, van Leeuwen E, Watson CH, Crofts J, Flasche S, et al. Protecting infants against RSV disease: an impact and cost-effectiveness comparison of long-acting monoclonal antibodies and maternal vaccination. Lancet Reg Health - Europe. 2024;38:100829. https://doi.org/10.1016/j.lanepe.2023.100829 . Shoukat A, Abdollahi E, Galvani AP, Halperin SA, Langley JM, Moghadas SM. Cost-effectiveness analysis of nirsevimab and maternal RSVpreF vaccine strategies for prevention of Respiratory Syncytial Virus disease among infants in Canada: a simulation study. Lancet Reg Health - Americas. 2023;28:100629. https://doi.org/10.1016/j.lana.2023.100629 . Mahmud S, Baral R, Sanderson C, Pecenka C, Jit M, Li Y, et al. Cost-effectiveness of pharmaceutical strategies to prevent respiratory syncytial virus disease in young children: a decision-support model for use in low-income and middle-income countries. BMC Med. 2023;21:138. https://doi.org/10.1186/s12916-023-02827-5 . Koltai M, Moyes J, Nyawanda B, Nyiro J, Munywoki PK, Tempia S, et al. Estimating the cost-effectiveness of maternal vaccination and monoclonal antibodies for respiratory syncytial virus in Kenya and South Africa. BMC Med. 2023;21:120. https://doi.org/10.1186/s12916-023-02806-w . Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 29 Dec, 2025 Reviewers agreed at journal 21 Dec, 2025 Reviewers invited by journal 19 Dec, 2025 Editor invited by journal 07 Nov, 2025 Editor assigned by journal 14 Oct, 2025 Submission checks completed at journal 14 Oct, 2025 First submitted to journal 13 Oct, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7850182","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":563673232,"identity":"12b8e6b1-6fbe-454c-a6bb-97451ee3d852","order_by":0,"name":"Zhiyuan Zhong","email":"","orcid":"","institution":"The Seventh Affiliated Hospital of Sun Yat-sen University","correspondingAuthor":false,"prefix":"","firstName":"Zhiyuan","middleName":"","lastName":"Zhong","suffix":""},{"id":563673233,"identity":"fc6aa094-264a-41ff-a23a-f1e966cb66af","order_by":1,"name":"Mengyuan He","email":"","orcid":"","institution":"The Seventh Affiliated Hospital of Sun Yat-sen University","correspondingAuthor":false,"prefix":"","firstName":"Mengyuan","middleName":"","lastName":"He","suffix":""},{"id":563673234,"identity":"b995466e-0e3d-4734-af7c-12d0b4405269","order_by":2,"name":"Xiaoyu Li","email":"","orcid":"","institution":"The Seventh Affiliated Hospital of Sun Yat-sen University","correspondingAuthor":false,"prefix":"","firstName":"Xiaoyu","middleName":"","lastName":"Li","suffix":""},{"id":563673235,"identity":"4449719c-fa14-4127-b38e-cd729b8be9c3","order_by":3,"name":"Wenqi Yu","email":"","orcid":"","institution":"The Seventh Affiliated Hospital of Sun Yat-sen University","correspondingAuthor":false,"prefix":"","firstName":"Wenqi","middleName":"","lastName":"Yu","suffix":""},{"id":563673236,"identity":"d0232b6e-0e30-43cb-9d6c-78b73b178d81","order_by":4,"name":"Su Liu","email":"","orcid":"","institution":"The Seventh Affiliated Hospital of Sun Yat-sen University","correspondingAuthor":false,"prefix":"","firstName":"Su","middleName":"","lastName":"Liu","suffix":""},{"id":563673237,"identity":"285a85a9-d924-4b1d-9379-0c5e9d92820e","order_by":5,"name":"Ran Yao","email":"","orcid":"","institution":"The Seventh Affiliated Hospital of Sun Yat-sen University","correspondingAuthor":false,"prefix":"","firstName":"Ran","middleName":"","lastName":"Yao","suffix":""},{"id":563673238,"identity":"799a2a0c-c768-41b6-8a10-48ca6a4521bd","order_by":6,"name":"Junfeng Xie","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA9UlEQVRIiWNgGAWjYDACZgYGAwYGORDrAFjAgEgtxkAWWwKRWiAApIXHgDgtBseZDxTz7jCQM+df8/kzz5/D9uYMzA8f3cCjRbKZLcGY94yBseWMt9ukedsOJ+5sYDM2zsGjhZ+Zx8CYt+1P4oYbZ7cx8zYcTjA4wMMmjU8LGzP/B6AWg/oNN848BjuMoBagLQwgLQkG53sYpHnYDjNuIKQF6BcDw7ltBoYbbrCZSc5tS0/ccJiAXwzOH35m8LbNQB7IePzhzR9re4PjzQ8f49MC8g4kJiQSGJh4QAxm/MrBSh5AfHWAgfEHYdWjYBSMglEwAgEAJ49JyRPqWm8AAAAASUVORK5CYII=","orcid":"","institution":"The Seventh Affiliated Hospital of Sun Yat-sen University","correspondingAuthor":true,"prefix":"","firstName":"Junfeng","middleName":"","lastName":"Xie","suffix":""}],"badges":[],"createdAt":"2025-10-13 14:38:19","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7850182/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7850182/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":98770921,"identity":"28ca166f-8cb4-4dc9-92e8-28cd0e68da93","added_by":"auto","created_at":"2025-12-22 10:39:49","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":129451,"visible":true,"origin":"","legend":"","description":"","filename":"AnalysisofRiskFactorsforPediatricRespiratorySyncytialVirusPneumoniaandOptimizationofVaccinationStrategies10.13.docx","url":"https://assets-eu.researchsquare.com/files/rs-7850182/v1/d06b2ad5b6479f9aa8e8a1c7.docx"},{"id":98770935,"identity":"7b3e99e3-23b6-4c7d-8321-2a0f213bd193","added_by":"auto","created_at":"2025-12-22 10:39:52","extension":"json","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":8504,"visible":true,"origin":"","legend":"","description":"","filename":"fb7dbf1c5e5a4c3b9f8a930a7bab07f2.json","url":"https://assets-eu.researchsquare.com/files/rs-7850182/v1/f7c8a2a5a2540bd0139b64b9.json"},{"id":98770927,"identity":"e299b4e1-36f1-427e-b2ab-c811c93e5f7c","added_by":"auto","created_at":"2025-12-22 10:39:50","extension":"xml","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":99818,"visible":true,"origin":"","legend":"","description":"","filename":"fb7dbf1c5e5a4c3b9f8a930a7bab07f21enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7850182/v1/5d353d784cd2b1452a3a8a6b.xml"},{"id":98770929,"identity":"8660736c-8028-405a-8f11-e182f9f1da99","added_by":"auto","created_at":"2025-12-22 10:39:50","extension":"png","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":24565,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7850182/v1/525d75d0a61e927a8fbde3ac.png"},{"id":98770853,"identity":"abe98a92-297b-4056-b753-a6df1ceb3d7b","added_by":"auto","created_at":"2025-12-22 10:39:48","extension":"xml","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":96582,"visible":true,"origin":"","legend":"","description":"","filename":"fb7dbf1c5e5a4c3b9f8a930a7bab07f21structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7850182/v1/429788c260e1ecde35602cce.xml"},{"id":98770939,"identity":"a23c2c54-b8c3-49fc-ac90-c26e707c8fdb","added_by":"auto","created_at":"2025-12-22 10:39:55","extension":"html","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":109345,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7850182/v1/d6aab5ced1d0468d992dc0ed.html"},{"id":98779197,"identity":"a0ae19f9-f1f1-488e-9880-c06f835832e2","added_by":"auto","created_at":"2025-12-22 12:30:04","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":114880,"visible":true,"origin":"","legend":"\u003cp\u003eFlowchart of the selection process for children with severe and non-severe RSV.\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7850182/v1/44e01bd69667621cfa486d76.jpeg"},{"id":98783338,"identity":"add0c180-d199-46ac-899b-6695019536e3","added_by":"auto","created_at":"2025-12-22 12:41:45","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":747170,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7850182/v1/9d6fbe85-360d-43a5-83ba-3ba3be9e9fba.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Analysis of Risk Factors for Pediatric Respiratory Syncytial Virus Pneumonia and Optimization of Vaccination Strategies","fulltext":[{"header":"Background","content":"\u003cp\u003eRespiratory syncytial virus (RSV) is the predominant etiological agent responsible for acute lower respiratory tract infections (LRTIs) in infants and young children, and it constitutes a major cause of hospitalization due to pneumonia and other LRTIs within this demographic [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. On a global scale, RSV is implicated in an estimated 33\u0026nbsp;million instances of acute LRTI among children aged 0 to 60 months, contributing to 2.0% of mortalities within this age group. Importantly, over 95% of RSV-related LRTI cases and more than 97% of RSV-associated deaths occur in low- and middle-income countries (LMICs) [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eCurrently, the management of RSV infection predominantly involves supportive care, as specific antiviral therapies are not yet available. Severe RSV infections place a substantial burden on healthcare systems and economies [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Consequently, the development of effective prevention and treatment strategies is imperative. Presently, the primary preventive measure against RSV infection is the use of monoclonal antibodies (mAbs) [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Although several RSV mAbs are undergoing clinical development, their widespread adoption has been hindered by high costs, the necessity for monthly administration, and restrictive eligibility criteria [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Therefore, it is crucial to analyze the risk factors associated with severe versus non-severe RSV infection to identify target populations for vaccination.\u003c/p\u003e \u003cp\u003eNumerous studies have demonstrated that independent risk factors for respiratory syncytial virus (RSV) infection are significantly correlated with younger age, premature birth, and the presence of comorbidities, particularly cardiovascular and pulmonary diseases, as well as certain genetic disorders [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Additionally, other underlying medical conditions that may heighten the risk of young children progressing from mild to severe illness and increase mortality rates require further investigation [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan additionalcitationids=\"CR14\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. In light of this, our study examines the clinical data of patients with RSV pneumonia to identify risk factors contributing to the development of severe RSV pneumonia (SRSVP) and to explore their potential implications for vaccination strategies.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy Subjects\u003c/h2\u003e \u003cp\u003eWe conducted a retrospective cohort study of patients treated for RSV infection at The Seventh Affiliated Hospital of Sun Yat-sen University, collecting medical record data for all patients diagnosed with RSV infection between April 2023 and August 2025. The Institutional Review Board of the Seventh Affiliated Hospital of Sun Yat-sen University approved this study and waived informed consent due to its retrospective design and the use of deidentified data. This study adhered strictly to the principles of the 1964 Declaration of Helsinki and its subsequent amendments and was approved by the Medical Ethics Committee of The Seventh Affiliated Hospital of Sun Yat-sen University (Approval No.: KY-2024-312-01). Given the non-interventional and retrospective nature of the study, the ethics committee waived the requirement for written informed consent from patients and their legal guardians.\u003c/p\u003e \u003cp\u003eInclusion criteria were:1.(1) diagnosis of SRSVP according to the \u003cem\u003eGuidelines for the Diagnosis, Treatment, and Prevention of Respiratory Syncytial Virus Infection in Children (2024 Edition)\u003c/em\u003e [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] and the \u003cem\u003eGuidelines for the Management of Community-Acquired Pneumonia in Children (2024 Revision)\u003c/em\u003e [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003cem\u003e(2)\u003c/em\u003eage under 18 years.\u003c/p\u003e \u003cp\u003eExclusion criteria were: age over 18 years, leaving the hospital against medical advice, and underlying conditions such as severe malnutrition, chronic heart disease, congenital diseases, immunodeficiency, malignant tumors, or multiple traumas.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eVariables and Outcome Measurement\u003c/h3\u003e\n\u003cp\u003eWe collected patient case data from the pediatric inpatient records of The Seventh Affiliated Hospital of Sun Yat-sen University to obtain baseline characteristics of eligible patients. This included information on age, sex, weight, height, season of onset, preterm birth, history of wheezing, eczema, history of allergies, and whether the patient had siblings, as detailed in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eData analysis was performed using IBM SPSS Statistics (Version 25.0; IBM Corporation, Armonk, NY, USA). Descriptive statistics were presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD), median (interquartile range), or counts and percentages, depending on the data type. Continuous variables were expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD or median (interquartile range) and compared using paired t-tests or Wilcoxon rank-sum tests. Categorical variables were reported as counts and percentages and compared using the chi-square test.\u003c/p\u003e \u003cp\u003eTo identify risk factors associated with RSV infection, we constructed a multivariate logistic regression model, calculating odds ratios (OR) and their corresponding 95% confidence intervals (CI), with statistical significance set at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05. Due to multicollinearity among age, height, and weight, we conducted two separate regression analyses. The multivariate regression model was built using baseline variables that were clinically significant or had a P-value\u0026thinsp;\u0026lt;\u0026thinsp;0.2 in the univariate analysis. The selected variables were carefully screened to ensure the interpretability of the final model. Additionally, we constructed a Receiver Operating Characteristic (ROC) curve to predict indicators of respiratory failure.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eBetween April 2023 and August 2025, a total of 387 patients hospitalized for RSV infection were admitted to the Children's Medical Center of the Seventh Affiliated Hospital of Sun Yat-sen University. Of these, 350 patients met the diagnostic criteria for RSV pneumonia. During the initial screening process, 37 patients (9.6%) were excluded because they did not meet the study inclusion criteria. The reasons for exclusion were as follows: 19 patients were diagnosed with upper respiratory tract infection, 5 patients discharged without medical advice, 1 patient had severe protein malnutrition, 9 patients had malignancies, 1 patient was admitted for multiple trauma, and 2 patients were adults. The final 350 patients were included in the analysis, of whom 157 (44.9%) were diagnosed with SRSVP and 193 (55.1%) with nonsevere RSV pneumonia (NRSVP) (see Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\n\u003ch3\u003eGeneral information of SRSVP and NRSVP groups\u003c/h3\u003e\n\u003cp\u003eIn this study, we conducted a detailed analysis of the basic characteristics of 193 patients with NRSVP and 157 patients with SRSVP. The results showed that the mean age, weight, and height of NRSVP patients were 1 year, 10 kg, and 76 cm, respectively; whereas the mean age, weight, and height of SRSVP patients were 0.8 years, 9.6 kg, and 74 cm, respectively. Statistical analysis revealed statistically significant differences in age, weight, and height between the two groups (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), with the SRSVP group showing lower age, weight, and height than the NRSVP group. Furthermore, the SRSVP group had a higher proportion of patients with siblings (51.6% vs. 39.4%, P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), potentially suggesting that family environment has a role in disease severity.\u003c/p\u003e \u003cp\u003eRegarding other clinical characteristics, no significant differences were found between the two groups in body mass index, sex, season of onset, birth during epidemic season, history of prematurity, history of wheezing, or history of eczema (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05). This suggests that these factors may not be the primary factors affecting the severity of RSV pneumonia. These results provide important clues for further exploring the potential factors affecting the severity of RSV pneumonia. Detailed data are shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eParticipation characteristics\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCharacteristics\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-severe\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;193)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSevere\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;157)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (years)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.0(0.6, 2.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.8(0.4, 2.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWeight (kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10.0(8.0,13.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.6(7.5,12.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.026\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHeight (cm)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e76.0(70.0,90.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e74.0(66.0,87.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16.4(15.3,17.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16.4(15.2,18.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.478\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBorn in epidemic season\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e80(41.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e74(47.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.287\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSeason of onset\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e/\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e/\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e/\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSpring\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e54(28.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e44(28.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.844\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSummer\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e108(56.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e86(54.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e/\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAutumn\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21(10.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21(13.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e/\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWinter\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10(5.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6(3.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e/\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e121(62.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e96(61.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.767\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e72(37.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e61(38.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e/\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePreterm birth\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14(7.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19(12.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.123\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHistory of wheezing\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11(5.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14(8.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.245\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHistory of eczema\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7(3.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6(3.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.924\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHistory of allergy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18(9.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8(5.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.133\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHaving siblings\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e76(39.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e81(51.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.022\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eLogistic Multivariate Regression Analysis Between SRSVP and NRSVP Groups\u003c/h2\u003e \u003cp\u003eBased on the results of the univariate analysis, we conducted a further logistic multivariate regression analysis to identify independent risk factors for severe respiratory syncytial virus pneumonia(Having siblings: odds ratio 1.568, 95% CI 1.015\u0026ndash;2.421, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.043; Weight: odds ratio 0.939, 95% CI 0887,0.995, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.032;Model:Logit(P)\u0026thinsp;=\u0026thinsp;0.45 \u0026times; Having siblings\u0026thinsp;+\u0026thinsp;0.627 \u0026times; History of wheezing \u0026minus;\u0026thinsp;0.156 \u0026times; History of eczema \u0026minus;\u0026thinsp;0.0516 \u0026times; History of allergy\u0026thinsp;+\u0026thinsp;0.436 \u0026times; Preterm birth \u0026minus;\u0026thinsp;0.063 \u0026times; Weight\u0026thinsp;+\u0026thinsp;0.192). The results showed that having siblings and lower body weight were independent risk factors for SRSVP. Detailed data are shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMultivariate analysis between SRSVP and NRSVP groups\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCharacteristic\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStd. Error\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eWald\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003edf\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eSig.\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eExp\u003c/p\u003e \u003cp\u003e(B)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e \u003cp\u003e95% C.I. for EXP\u003c/p\u003e \u003cp\u003e(B)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHaving siblings\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.450\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.222\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.110\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.043\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e1.568\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1.015, 2.421\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHistory of wheezing\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.627\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.438\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.046\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.153\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e1.871\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.793, 4.415\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHistory of eczema\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.156\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.590\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.070\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.791\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e0.856\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.269, 2.718\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHistory of allergy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.0516\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.467\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.218\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.270\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e0.597\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.239, 1.492\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePreterm birth\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.436\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.380\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.316\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.251\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e1.547\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.734, 3.261\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWeight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.063\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.029\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.578\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.032\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e0.939\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.887, 0.995\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eConstant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.192\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.341\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.317\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.573\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cp\u003e1.212\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study investigated 387 children hospitalized for RSV-related acute respiratory infections at the Pediatric Medical Center of The Seventh Affiliated Hospital of Sun Yat-sen University during the 2023\u0026ndash;2025 respiratory virus season. Among them, 157 children were diagnosed with severe disease, 193 with non-severe disease, and 37 were excluded for not meeting the inclusion criteria. Severe cases were observed across all age groups, including previously healthy children and those with chronic conditions. The study found that risk factors for severe disease included having siblings (P\u0026thinsp;=\u0026thinsp;0.043) and low body weight (P\u0026thinsp;=\u0026thinsp;0.032). These results reveal the evolving clinical factors of pediatric RSV infection based on current epidemiological characteristics, suggesting that such patients are more suitable candidates for vaccination.\u003c/p\u003e \u003cp\u003eOur study found that the median weight of patients in the SRSVP group was lower than that of the NRSVP group (9.6 kg vs. 10.0 kg). Additionally, a higher proportion of patients in the SRSVP group had siblings. Previous research has indicated that low body weight is a major risk factor for severe RSV disease in children, and infants hospitalized with RSV-related illness are at high risk for requiring intensive care and longer hospital stays [\u003cspan additionalcitationids=\"CR19\" citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Similarly, having siblings is a significant predictor of disease severity, especially having older siblings, possibly because older children are more likely to introduce RSV into the household [\u003cspan additionalcitationids=\"CR22\" citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Our research further suggests that vaccination strategies should prioritize children with lower body weight and those with siblings.\u003c/p\u003e \u003cp\u003eIn previous studies, age and a history of preterm birth have been considered major risk factors for severe RSV infection [\u003cspan additionalcitationids=\"CR25\" citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. However, in our study, age and preterm birth did not show significant differences in the univariate analysis. This does not negate their role as risk factors but may be attributed to the widespread adoption of proactive preventive measures for high-risk infants, such as preterm babies, in recent years, including the use of RSV immunoprophylaxis agents like palivizumab [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Our study cohort may have benefited from these interventions, which could have mitigated the inherent risk of severe disease associated with preterm birth, rendering it statistically non-significant in our analysis. Furthermore, the sample size might have been insufficient to detect smaller but genuine effect differences related to age or preterm birth. Nevertheless, the trends we observed are consistent with the general direction of previous literature: the proportion of preterm infants was slightly higher in the severe group than in the non-severe group (12.1% vs. 7.3%), and the severe group was younger (0.8 years vs. 1.0 year). Although these differences did not reach statistical significance, the trends are notable.\u003c/p\u003e \u003cp\u003eThe cost and cost-effectiveness of RSV-related products are critical factors in the decision-making processes of all countries. Product pricing varies by country, which decisively affects affordability and cost-effectiveness. Multiple studies have shown that, depending on the price and target population, both mAb and vaccine strategies can be cost-effective in high-income and low- and middle-income countries alike [\u003cspan additionalcitationids=\"CR30 CR31\" citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. Our study suggests that vaccination or mAb administration should be prioritized for high-risk pediatric populations, such as patients with siblings or lower body weight, who are more likely to develop severe RSV infection. Prioritizing these children for vaccination in the next epidemic season could not only effectively prevent severe RSV infections but also significantly reduce medical expenditures for patients and productivity losses for caregivers.\u003c/p\u003e \u003cp\u003eThis study has several limitations that require consideration. First, due to its retrospective design, inherent biases are unavoidable. Second, this study included only hospitalized patients, which may limit the generalizability of the findings. Furthermore, we did not perform prospective, external, or internal validation of our model to more comprehensively explore the prevalence of RSV, which may affect the reliability of our results. Finally, the data in this study were obtained from a single center with a relatively small sample size, which limited our ability to adjust for multiple covariates and may affect the generalizability of our results. In future studies, we plan to include outpatients and validate these results using a more diverse dataset to improve the generalizability of our study.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eOur analysis of clinical data from patients with RSV pneumonia indicates a significant association between the risk of developing SRSVP and the patient's epidemiological characteristics. Through multivariate logistic regression analysis, we identified the presence of siblings and lower body weight as independent predictors for the onset of SRSVP. Consequently, this study advocates for RSV prevention strategies that encompass all infants and young children, with a particular focus on those with siblings and lower body weight. These indicators offer clinicians a practical approach for the rapid identification of \"ultra-high-risk\" children. Prioritizing vaccination for these children is anticipated to confer the greatest health benefits.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003cstrong\u003eEthical approval\u003c/strong\u003e \u003cp\u003e This study strictly adhered to the principles of the Declaration of Helsinki and received formal approval from the Ethics Committee of the Seventh Affiliated Hospital of Sun Yat-sen University before the study began. Given the use of de-identified secondary data and the fact that data collection was completed through a retrospective review of medical records, no informed consent was required. Instead, a waiver of informed consent was obtained from the Institutional Review Board of the Seventh Affiliated Hospital of Sun Yat-sen University, in accordance with relevant laws and regulations regarding the protection of participants' rights, welfare, and privacy. To ensure patient privacy, no sensitive personal information, such as names and medical record numbers, was included during data collection.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eCompeting interests\u003c/strong\u003e \u003cp\u003eThe authors declare that they have no conflicts ofinterest.\u003c/p\u003e \u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eNobody funding this research.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eZhiyuan Zhong, Mengyuan he, Xiaoyu Li, Mengqi Yu, Ran Yao, Su Liu and Junfeng Xie contributed to the study conception and design. Material preparation, data collection and analysis were performed by Zhiyuan Zhong, Mengyuan He, Xiaoyu Li, Mengqi Yu. The first draft of the manuscript was written by Zhiyuan Zhong, Mengyuan he, Xiaoyu Li. Ran Yao, Su Liu and Junfeng commented on previous versions of the manuscript. Zhiyuan Zhong, Mengyuan he, Xiaoyu Li, Mengqi Yu, Ran Yao, Su Liu and Junfeng read and approved the final manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgements\u003c/h2\u003e \u003cp\u003eWe would like to thank Prof. Feiqiu Wen and Prof. Chi-kong Li for their guidance on this thesis.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eMainly result-based data are available within the manuscript, for those who need full data and additional material related to the manuscript can be obtained from the Corresponding author with a reasonable formal request via email; [[email protected]](mailto:[email protected])\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eXu H, Aparicio C, Wats A, Araujo BL, Pitzer VE, Warren JL, et al. Estimated Effectiveness of Nirsevimab Against Respiratory Syncytial Virus. JAMA Netw Open. 2018;8:e250380. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1001/jamanetworkopen.2025.0380\u003c/span\u003e\u003cspan address=\"10.1001/jamanetworkopen.2025.0380\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKarron RA. Preventing respiratory syncytial virus (RSV) disease in children. Science. 2021;372:686\u0026ndash;7. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1126/science.abf9571\u003c/span\u003e\u003cspan address=\"10.1126/science.abf9571\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi Y, Wang X, Blau DM, Caballero MT, Feikin DR, Gill CJ, et al. Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in children younger than 5 years in 2019: a systematic analysis. Lancet. 2022;399:2047\u0026ndash;64. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S0140-6736(22)00478-0\u003c/span\u003e\u003cspan address=\"10.1016/S0140-6736(22)00478-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJefferies K, Drysdale SB, Robinson H, Clutterbuck EA, Blackwell L, McGinley J, et al. Presumed Risk Factors and Biomarkers for Severe Respiratory Syncytial Virus Disease and Related Sequelae: Protocol for an Observational Multicenter, Case-Control Study From the Respiratory Syncytial Virus Consortium in Europe (RESCEU). J Infect Dis. 2020;222 Supplement7:S658\u0026ndash;65. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/infdis/jiaa239\u003c/span\u003e\u003cspan address=\"10.1093/infdis/jiaa239\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGeoghegan S, Erviti A, Caballero MT, Vallone F, Zanone SM, Losada JV, et al. Mortality due to Respiratory Syncytial Virus. Burden and Risk Factors. Am J Respir Crit Care Med. 2017;195:96\u0026ndash;103. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1164/rccm.201603-0658OC\u003c/span\u003e\u003cspan address=\"10.1164/rccm.201603-0658OC\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRoymans D, Alnajjar SS, Battles MB, Sitthicharoenchai P, Furmanova-Hollenstein P, Rigaux P, et al. Therapeutic efficacy of a respiratory syncytial virus fusion inhibitor. Nat Commun. 2014;8:167. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/s41467-017-00170-x\u003c/span\u003e\u003cspan address=\"10.1038/s41467-017-00170-x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSnyder BM, Achten NB, Gebretsadik T, Wu P, Mitchel EF, Escobar G, et al. Personalized Infant Risk Prediction for Severe Respiratory Syncytial Virus Lower Respiratory Tract Infection Requiring Intensive Care Unit Admission. Open Forum Infect Dis. 2024;11:ofae077. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/ofid/ofae077\u003c/span\u003e\u003cspan address=\"10.1093/ofid/ofae077\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePecenka C, Sparrow E, Feikin DR, Srikantiah P, Darko DM, Karikari-Boateng E, et al. Respiratory syncytial virus vaccination and immunoprophylaxis: realising the potential for protection of young children. Lancet. 2024;404:1157\u0026ndash;70. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S0140-6736(24)01699-4\u003c/span\u003e\u003cspan address=\"10.1016/S0140-6736(24)01699-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTerstappen J, Hak SF, Bhan A, Bogaert D, Bont LJ, Buchholz UJ, et al. The respiratory syncytial virus vaccine and monoclonal antibody landscape: the road to global access. Lancet Infect Dis. 2024;24:e747\u0026ndash;61. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S1473-3099(24)00455-9\u003c/span\u003e\u003cspan address=\"10.1016/S1473-3099(24)00455-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIshiwada N, Akaishi R, Kobayashi Y, Togo K, Yonemoto N, Matsuo M, et al. Cost-Effectiveness Analysis of Maternal Respiratory Syncytial Virus Vaccine in Protecting Infants from RSV Infection in Japan. Infect Dis Ther. 2024;13:1665\u0026ndash;82. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s40121-024-01000-6\u003c/span\u003e\u003cspan address=\"10.1007/s40121-024-01000-6\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMa H-Y, Lin I-F, Liu Y-C, Yen T-Y, Huang K-YA, Shih W-L, et al. Risk Factors for Severe Respiratory Syncytial Virus Infection in Hospitalized Children. Pediatr Infect Dis J. 2024;43:487\u0026ndash;92. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1097/INF.0000000000004270\u003c/span\u003e\u003cspan address=\"10.1097/INF.0000000000004270\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCurns AT, Rha B, Lively JY, Sahni LC, Englund JA, Weinberg GA, et al. Respiratory Syncytial Virus-Associated Hospitalizations Among Children \u0026lt;5 Years Old: 2016 to 2020. Pediatrics. 2024;153:e2023062574. https://doi.org/10.1542/peds.2023-062574.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRao S, Armistead I, Messacar K, Alden NB, Schmoll E, Austin E, et al. Shifting Epidemiology and Severity of Respiratory Syncytial Virus in Children During the COVID-19 Pandemic. JAMA Pediatr. 2023;177:730. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1001/jamapediatrics.2023.1088\u003c/span\u003e\u003cspan address=\"10.1001/jamapediatrics.2023.1088\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMa H-Y, Lin I-F, Liu Y-C, Yen T-Y, Huang K-YA, Shih W-L, et al. Risk Factors for Severe Respiratory Syncytial Virus Infection in Hospitalized Children. Pediatr Infect Disease J. 2024;43:487\u0026ndash;92. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1097/INF.0000000000004270\u003c/span\u003e\u003cspan address=\"10.1097/INF.0000000000004270\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSudnik P, Walsh EE, Branche AR, Islam MR, Falsey AR. Comprehensive Analysis of Cardiovascular Events and Risk Factors in Patients Hospitalized With Respiratory Syncytial Virus. Clin Infect Dis. 2025;ciaf310. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/cid/ciaf310\u003c/span\u003e\u003cspan address=\"10.1093/cid/ciaf310\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuideline for the. diagnosis, treatment, and prevention of respiratory syncytial virus infection in children in China. Pediatr Invest. 2025;9:205\u0026ndash;20. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1002/ped4.70010\u003c/span\u003e\u003cspan address=\"10.1002/ped4.70010\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSubspecialty Group of Respiratory, the Society of Pediatrics, Chinese Medical Association, Board E, Chinese Journal of Pediatrics, China Medicine Education Association Committee on Pediatrics. [Guidelines for the management of community-acquired pneumonia in children (2024 revision)]. Zhonghua Er Ke Za Zhi. 2024;62:920\u0026ndash;30. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3760/cma.j.cn112140-20240728-00523\u003c/span\u003e\u003cspan address=\"10.3760/cma.j.cn112140-20240728-00523\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang Y, Xiang Y, Jin R, Li B, Feng X, Han Q, et al. Risk factors for severe lower respiratory tract infection among children under 5 years of age hospitalized with respiratory syncytial virus. Eur J Clin Microbiol Infect Dis. 2025;44:2239\u0026ndash;51. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s10096-025-05191-9\u003c/span\u003e\u003cspan address=\"10.1007/s10096-025-05191-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTielsch JM, Steinhoff M, Katz J, Englund JA, Kuypers J, Khatry SK, et al. Designs of two randomized, community-based trials to assess the impact of influenza immunization during pregnancy on respiratory illness among pregnant women and their infants and reproductive outcomes in rural Nepal. BMC Pregnancy Childbirth. 2015;15:40. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1186/s12884-015-0470-y\u003c/span\u003e\u003cspan address=\"10.1186/s12884-015-0470-y\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTamir S, Golan-Tripto I, Hazan I, Adar A, Burrack N, Cohen B, et al. Does weight influence the course of RSV bronchiolitis in hospitalized infants? Eur J Pediatr. 2024;183:2663\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00431-024-05521-7\u003c/span\u003e\u003cspan address=\"10.1007/s00431-024-05521-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHavdal LB, B\u0026oslash;\u0026aring;s H, Bekkevold T, Bakken Kran A-M, Rojahn AE, St\u0026oslash;rdal K, et al. Risk factors associated with severe disease in respiratory syncytial virus infected children under 5 years of age. Front Pediatr. 2022;10:1004739. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/fped.2022.1004739\u003c/span\u003e\u003cspan address=\"10.3389/fped.2022.1004739\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDeng S, Cong B, Edgoose M, De Wit F, Nair H, Li Y. Risk factors for respiratory syncytial virus-associated acute lower respiratory infection in children under 5 years: An updated systematic review and meta-analysis. Int J Infect Dis. 2024;146:107125. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ijid.2024.107125\u003c/span\u003e\u003cspan address=\"10.1016/j.ijid.2024.107125\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZylbersztejn A, Pembrey L, Goldstein H, Berbers G, Schepp R, van der Klis F, et al. Respiratory syncytial virus in young children: community cohort study integrating serological surveys, questionnaire and electronic health records, Born in Bradford cohort, England, 2008 to 2013. Euro Surveill. 2021;26:2000023. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.2807/1560-7917.ES.2021.26.6.2000023\u003c/span\u003e\u003cspan address=\"10.2807/1560-7917.ES.2021.26.6.2000023\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePapenburg J, Hamelin M-\u0026Egrave;, Ouhoummane N, Carbonneau J, Ouakki M, Raymond F, et al. Comparison of risk factors for human metapneumovirus and respiratory syncytial virus disease severity in young children. J Infect Dis. 2012;206:178\u0026ndash;89. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/infdis/jis333\u003c/span\u003e\u003cspan address=\"10.1093/infdis/jis333\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu H-F, Wang Y-Y, Zhang X-Z, Li H-Y, Xiang M, Lu R, et al. Comparison of characteristics of children hospitalized for respiratory syncytial virus infection during the pre- and post-COVID-19 eras: a multicenter retrospective study. BMC Infect Dis. 2024;24:1009. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1186/s12879-024-09783-2\u003c/span\u003e\u003cspan address=\"10.1186/s12879-024-09783-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKobiałka M, Jackowska T, Wrotek A. Risk Factors for Severe Respiratory Syncytial Virus Infection in Hospitalized Children. Viruses. 2023;15:1713. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/v15081713\u003c/span\u003e\u003cspan address=\"10.3390/v15081713\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrady MT, Byington CL, Davies HD, Edwards KM, Jackson MA, Maldonado YA, et al. Updated guidance for palivizumab prophylaxis among infants and young children at increased risk of hospitalization for respiratory syncytial virus infection. Pediatrics. 2014;134:415\u0026ndash;20. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1542/peds.2014-1665\u003c/span\u003e\u003cspan address=\"10.1542/peds.2014-1665\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGriffin MP, Yuan Y, Takas T, Domachowske JB, Madhi SA, Manzoni P, et al. Single-Dose Nirsevimab for Prevention of RSV in Preterm Infants. N Engl J Med. 2020;383:415\u0026ndash;25. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1056/NEJMoa1913556\u003c/span\u003e\u003cspan address=\"10.1056/NEJMoa1913556\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHodgson D, Wilkins N, van Leeuwen E, Watson CH, Crofts J, Flasche S, et al. Protecting infants against RSV disease: an impact and cost-effectiveness comparison of long-acting monoclonal antibodies and maternal vaccination. Lancet Reg Health - Europe. 2024;38:100829. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.lanepe.2023.100829\u003c/span\u003e\u003cspan address=\"10.1016/j.lanepe.2023.100829\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShoukat A, Abdollahi E, Galvani AP, Halperin SA, Langley JM, Moghadas SM. Cost-effectiveness analysis of nirsevimab and maternal RSVpreF vaccine strategies for prevention of Respiratory Syncytial Virus disease among infants in Canada: a simulation study. Lancet Reg Health - Americas. 2023;28:100629. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.lana.2023.100629\u003c/span\u003e\u003cspan address=\"10.1016/j.lana.2023.100629\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMahmud S, Baral R, Sanderson C, Pecenka C, Jit M, Li Y, et al. Cost-effectiveness of pharmaceutical strategies to prevent respiratory syncytial virus disease in young children: a decision-support model for use in low-income and middle-income countries. BMC Med. 2023;21:138. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1186/s12916-023-02827-5\u003c/span\u003e\u003cspan address=\"10.1186/s12916-023-02827-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKoltai M, Moyes J, Nyawanda B, Nyiro J, Munywoki PK, Tempia S, et al. Estimating the cost-effectiveness of maternal vaccination and monoclonal antibodies for respiratory syncytial virus in Kenya and South Africa. BMC Med. 2023;21:120. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1186/s12916-023-02806-w\u003c/span\u003e\u003cspan address=\"10.1186/s12916-023-02806-w\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-infectious-diseases","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"infd","sideBox":"Learn more about [BMC Infectious Diseases](http://bmcinfectdis.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/infd","title":"BMC Infectious Diseases","twitterHandle":"#bmcinfectdis","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Respiratory syncytial virus pneumonia, Severe, Vaccination, Predictors, Children","lastPublishedDoi":"10.21203/rs.3.rs-7850182/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7850182/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eObjective\u003c/h2\u003e \u003cp\u003eThe study focuses on pneumonia in children caused by respiratory syncytial virus (RSV), which is linked to high morbidity, hospitalization, and mortality rates. It aims to enhance pediatric vaccination strategies by examining the clinical differences between severe and non-severe RSV pneumonia cases.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eConducted from April 2023 to August 2025, this retrospective study used electronic medical records from the Pediatric Medical Center at The Seventh Affiliated Hospital of Sun Yat-sen University. We analyzed 387 hospitalized children with RSV, assessing risk factors through univariate and multivariate logistic regression.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eBased on the inclusion and exclusion criteria, 350 patients were included in the final analysis. Among these, 157 patients (44.9%) were diagnosed with severe respiratory syncytial virus pneumonia (SRSVP), while 193 patients (55.1%) were diagnosed with non-severe respiratory syncytial virus pneumonia (NRSVP). Through multivariate logistic regression analysis, the presence of siblings and low body weight were identified as significant risk factors for the development of SRSVP(Having siblings: odds ratio 1.568, 95% CI 1.015\u0026ndash;2.421, P\u0026thinsp;=\u0026thinsp;0.043; Weight: odds ratio 0.939, 95% CI 0887,0.995, P\u0026thinsp;=\u0026thinsp;0.032).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eThe study concludes that the risk of developing severe respiratory syncytial virus pneumonia (SRSVP) is significantly associated with specific epidemiological characteristics of the patient. Notably, having siblings and low body weight emerged as independent predictors for the onset of SRSVP.\u003c/p\u003e","manuscriptTitle":"Analysis of Risk Factors for Pediatric Respiratory Syncytial Virus Pneumonia and Optimization of Vaccination Strategies","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-22 10:38:27","doi":"10.21203/rs.3.rs-7850182/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2025-12-29T15:34:17+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"24532377363483996634737258937267994372","date":"2025-12-21T15:24:59+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-12-19T13:09:32+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-11-07T07:03:01+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-10-15T00:54:10+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-15T00:53:03+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Infectious Diseases","date":"2025-10-13T14:30:52+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-infectious-diseases","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"infd","sideBox":"Learn more about [BMC Infectious Diseases](http://bmcinfectdis.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/infd","title":"BMC Infectious Diseases","twitterHandle":"#bmcinfectdis","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"a76d7ee6-546d-494a-bd6c-4bbc86f03f9a","owner":[],"postedDate":"December 22nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-12-22T10:38:27+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-22 10:38:27","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7850182","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7850182","identity":"rs-7850182","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}