Determinants of zero-dose children in Kamina, DR Congo

Determinants of zero-dose children in Kamina, DR Congo | 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 Determinants of zero-dose children in Kamina, DR Congo François Kalenga Luhembwe, Bertin Mindje Kolomba, Tristan Ilunga Kabale, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7158136/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Introduction : Vaccination is recognized as one of the most effective and cost-effective public health interventions. This work presents a summary of the factors that may explain the presence of zero-dose children in Congolese communities. Methods: This is a cross-sectional analytical study conducted between March 2024 and January 2025. The statistical units were children aged 12 to 23 months and the responding units were the mothers/guardians of these children selected through three (3) stage probability sampling. The data were collected using the SurveyCTO tool and analyzed using IBM SPSS 26 and Jamovi version 2.5.5 software. Cronbach's alpha coefficient allowed us to measure the internal consistency of the data. The associations were tested using the Pearson chi-square or Fischer exact test. The analysis of factors associated with zero-dose children was done using a multivariate logistic regression model of the "Wald Ascending" type. The Archer-Lemeshow test was used to assess the goodness of fit of the model and the ROC curve allowed us to evaluate the performance of the model. Results : The study indicated that the determinants of zero dose children in our environment are the mother's age less than or equal to 19 years (ORa= 10.996 [ 3.035 - 39.840 ]), the mother's low education level (ORa= 16.763 [ 2.230 - 125.991 ]), the mother's "unmarried" status (ORa= 16.436 [ 1.311 - 206.053 ]), the mother's occupation "worker" (ORa= 86.163 [ 12.839 - 578.252 ]), the child's home birth (ORa= 4.950 [ 1.127 - 21.748 ]), the perception that vaccination does not protect the child against diseases (ORa= 8,441 [ 2,385 - 29,872 ]) as well as the non-consideration of the recommendation of health personnel on the vaccination of the child (OR = 4,388 [ 1,254 - 15,354 ]). Conclusion : In order to reduce the incidence of zero-dose children, the study highlights the need to promote female education, deliveries in health facilities, communication activities and community engagement in favor of vaccination. Statistical Epidemiology determinants child zero dose Kamina Democratic Republic of Congo Introduction Vaccination saves millions of lives each year and is widely recognized as one of the most effective health interventions in the world. Yet, over the past decade, childhood vaccination coverage rates have plateaued at around 85%, leaving millions of children vulnerable to life-threatening diseases that vaccines can prevent. This plateau is deflecting the world from its goal of providing access to safe and effective medicines and vaccines for all, as outlined in the World Health Organization's 2030 Agenda for Immunization and the United Nations 2030 Agenda for Sustainable Development [ 1 ] . Globally, an estimated 21.8 million infants remain missing from routine immunization services. Of the 19.7 million children worldwide who did not receive all three doses of diphtheria, tetanus, and pertussis (DTP) vaccine in 2019, 13.8 million (70%) were zero-dose children [ 2 ]. This figure has increased sharply following the sudden onset of the COVID-19 pandemic, which has significantly disrupted essential lifesaving services such as routine immunization (RSV), increasing countries' vulnerability to outbreaks of vaccine-preventable diseases (VPDs) [ 3 ] . In Africa, approximately 33 million children will need to be vaccinated between 2023 and 2025 for the continent to meet the 2030 global immunization targets, including reducing morbidity and mortality from vaccine-preventable diseases, according to an analysis by the World Health Organization (WHO). The unprecedented impact of the COVID-19 pandemic on routine immunization services has led to an increase in the number of zero-dose and under-immunized children, a 16% increase between 2019 and 2021, bringing the cumulative total of these children (over the period 2019–2021) to approximately 33 million, representing almost half of the global number [ 4 ] . According to the UNICEF report, Africa is the region with the largest number of zero-dose or under-vaccinated children: 12.7 million children were under-vaccinated in 2021 and 8.7 million children had a zero-dose vaccination status. Half of the top 20 countries in the world with the largest number of zero-dose children are in Africa. Nigeria and Ethiopia are the two countries on the continent with the largest number of zero-dose children, with more than 2.2 million and 1.1 million children respectively. Two out of five zero-dose children in Africa live in one of these two countries [ 5 ] . In the Democratic Republic of Congo (DRC), despite progress in reducing under-five mortality, which fell from 158 per 1000 live births in 2007 [ 6 ] to 104 per 1000 live births in 2013 [ 7 ], and to 70 per 1000 live births in 2017 [ 8 ]. This excess mortality among children is largely attributable to vaccine-preventable diseases. In 2013, vaccination coverage estimates based on vaccination card information showed that only 41% of children aged 12 to 23 months had been fully vaccinated before the age of 12 months in the DRC. When information provided by the mother was taken into account, this percentage increased to 45% [ 7 ] . Each year, the DRC records seven hundred and eighty thousand (780,000) zero-dose children, while in 2022, 1.5 million children were insufficiently vaccinated. One in five (5), or 19%, is zero-dose, one in three (3) is insufficiently vaccinated and two (2) in five (5) have not received the three doses of DTP (diphtheria, tetanus, pertussis). Two-thirds (2/3) of zero-dose children come from the most central and rural areas of 10 of the country's 26 provinces. Among these 2/3 children, 75% live less than one kilometer from a health facility, while 90% are less than three kilometers away [ 9 ] . Numerous studies have been conducted in the Democratic Republic of Congo to identify factors associated with incomplete vaccination and low vaccination coverage [ 11 ] [ 11 ]. However, few of them have been conducted on zero-dose children. It is in this context that this study was conducted to determine the proportion and identify the determinants of zero-dose children in Kamina. Methods Study framework This study was conducted in the town of Kamina located in the Haut-Lomami Province in the Democratic Republic of Congo. The town of Kamina, capital of the Haut-Lomami province, is a decentralized administrative entity, with an estimated population of 366,557 inhabitants spread across sixteen districts. Its population 's main occupations are agriculture and small businesses. The main agricultural products are: corn, beans, sweet potatoes, peanuts. The population of children aged 12 to 23 months, the target of the PEV, is 35,595 [ 12 ] . Type, period and study population This is an observational study of a cross-sectional analytical type conducted between March 2024 and January 2025. The survey generally covered all households in the RVA, Urban Center, Kyabukwa, Katuba I, and Katuba IV health areas. The source population included households in all avenues of these selected health areas. The statistical units were children aged 12 to 23 months, and the responding units consisted of the mothers or guardians of these children. Sample and sampling A sample of 236 study participants was calculated at a specified 95% confidence interval and an acceptable margin of error of 5% (0.05). A national proportion of 0.19 or 19% of zero-dose children [ 9 ] was used in this study. This sample was calculated using the formula of Brown et al . [ 13 ]. The selection of statistical units was done using three (3) stage probability sampling. Data collection tools and techniques Using a previously tested electronic questionnaire configured on the SurveyCTO Collect tool, mothers or caregivers were interviewed about the vaccines received by the child before twelve (12) months. The information collected included socio-demographic characteristics, factors related to the vaccination system and the mothers' knowledge, attitudes and practices on vaccination. The vaccines received by the child were obtained from the vaccination card. Ethical considerations Ethical clearance was obtained from the Ethics Committee of the School of Public Health (Approval Letter No. UNILU/CEM/229/2024), the University of Lubumbashi, and the DRC, in accordance with the Declaration of Helsinki. Participants were informed that their participation was voluntary. Verbal and informed consent was obtained from each study participant, which was approved by the Ethics Committee. Processing and analysis of statistical data Data were analyzed using IBM SPSS 26 and Jamovi version 2.5.5 software. Input checks allowed us to minimize errors. Cronbach's alpha coefficient allowed us to measure the internal consistency or reliability of our data. We performed weighted flat sorting analyses of sociodemographic characteristics in the study sample with categorical variables reported as frequencies and percentages, where appropriate, and continuous variables summarized using means and standard deviations or medians and interquartile ranges, depending on the normality of the distribution using the Kolmogorov-Smirnov test. In the bivariate analysis, associations between the dependent variable and the independent variables were tested using the Pearson chi-square or Fischer exact test as appropriate. The odds ratio and its 95% confidence interval were calculated to measure the association between random variables. Analysis of factors associated with zero-dose children was performed using a multivariate logistic regression model of the “Wald Ascending” type. The Archer-Lemeshow test was used to assess the goodness of fit of the logistic regression model. The model performance was assessed using ROC analysis, which was considered acceptable after checking the AUC. Results Proportion of zero-dose children and sociodemographic characteristics : The results of this study show that the proportion of zero-dose children in our environment is 18.2%. The majority of mothers who participated in this study, 87.7%, were over 19 years old, 73.3% had a low level of education (none/primary), 97.0% were married, 90.7% were Christian, 83.5% were housewives or had a liberal activity. In relation to the child's place of birth, 3.4% of children were born at home ( Table 1 ). Relationship between zero-dose vaccination status and sociodemographic characteristics : The results of this study highlight that the probability of having a zero-dose vaccination status is statistically very high among children of unmarried, working mothers, with a low level of education (none/primary) and whose age less than or equal to 19 years (p˂0.05). Belonging to an ancestral church increases 14.235 [5.336 - 37.973] times the risk of zero-dose children. However, children born at home are 15.486 [3.008 -79.723 ] times more likely to be zero-dose ( Table 2 ). <p Relationship between zero-dose vaccination status and mother/caregiver perception of child vaccination : This study found that mothers or caretakers of children with a perception that vaccination according to the schedule does not protect the child against diseases are likely to have zero-dose children (p˂0.05). It should also be noted that children of mothers/caregivers who do not tend to act according to the recommendations of a health worker on vaccination run 17,490 [7,672 - 39,872] times the risk of being zero-dose ( Table 3 ). Logistic regression of the different determinants of zero-dose children : This study indicates that the determinants of zero-dose children in our environment are the mother's age less than or equal to 19 years (ORa= 10.996 [ 3.035 - 39.840 ]) , the mother's low level of education (ORa= 16.763 [ 2.230 - 125.991 ]) , the mother's "unmarried" status (ORa= 16.436 [ 1.311 - 206.053 ]) , the mother's occupation "worker" (ORa= 86.163 [ 12.839 - 578.252 ]) , the child's birth at home (ORa= 4.950 [ 1.127 - 21.748 ]) , having a perception according to which vaccination does not protect the child against diseases (ORa = 8.441 [ 2.385 - 29.872 ]) as well as the non-consideration of the recommendation of health personnel on the vaccination of the child (OR = 4.388 [ 1.254 - 15.354 ]) ( Table 4 ). ROC curve of determinants of zero-dose children : Discriminant factor analysis shows that the area under the curve (AUC) values in ( Figure 1 ) indicate a predictive capacity on zero-dose vaccination status of 0.919 or 91.9% (AUC between 0.857 and 0.981). Discussion Our study, one of the first of its kind in the Haut-Lomami province, reported a proportion of zero-dose children of 18.2%. This result, lower than that of 19.1% reported by Ishoso et al. [ 14 ], shows an improvement in vaccination coverage in our setting given that WHO and UNICEF have noted an increase in the prevalence of zero-dose children in sub-Saharan Africa from 6.8% in 2010 to 14% during the year of the COVID-19 pandemic of 2021 [ 1 ]. These results prove that the proportion of zero-dose children varies considerably between and within countries, with substantial heterogeneities in context. These results therefore highlight the variability of the proportion of zero children, both geographically and in terms of population characteristics, demonstrating the need for vaccination strategies appropriate to each country and each area, which take into account the size of the country, the available resources and the context in which the populations live. In this study, the probability of having a zero-dose vaccination status was statistically very high among children of mothers whose age was less than or equal to 19 years (p˂0.05). This result is consistent with a study conducted in Ethiopia [ 15 ]. According to several studies, the older the mother, the less hesitant and less obstacles she may encounter in getting her child vaccinated [ 16 ]. According to Ishoso et al., the young age of the mother is a significant factor in improving vaccination coverage [ 14 ] . The study found that low maternal education (none/primary) had a statistically significant association with the child's zero-dose vaccination status. The lower the maternal education, the greater the likelihood of being zero-dose. Numerous studies on full vaccination coverage of children aged 12 to 23 months and reasons for non-vaccination in peri-urban areas have also found the same result. [ 17 ]. Indeed, maternal education level has been associated with vaccination in most settings [ 18 ]. According to the results reported by Mohamud et al., literate mothers were 3.06 times more likely to fully vaccinate their children than illiterate mothers (AOR = 3.06, 95% CI = 1.64, 5.71) [ 16]. In other similar studies, maternal education level has been reported as a predictor of zero-dose children [ 19 ]. This may be because literate mothers have better knowledge of vaccine-preventable diseases and recognize the importance of vaccination. Consistent with studies conducted in Ethiopia by Abebe et al., [ 15 ], the present study also found that ancestral church affiliation increases the risk of zero-dose children 14,235 [5,336 − 37,973] times. In contrast to the Demographic and Health Surveys conducted by Ozigbu et al., in 33 sub-Saharan African countries, children of Muslims were significantly more likely to be zero-dose than children of Christians (25.2% vs. 12.3%) [ 20 ]. However, Santos et al., in an analysis of 66 low- and middle-income countries that have conducted standardized national surveys since 2010, found that the relationship between religion and vaccination was not consistent across the world [ 21 ]. The latter hypothesis suggests that various cultural and community factors may modulate the relationship between religious affiliation and vaccination [ 14 ]. Collaboration with religious leaders may be an appropriate solution. Our results, like those of Nchinjoh et al. [ 22 ] showed that children born at home are 15,486 [3,008–79,723] times more likely to be zero dose. This statistical difference is thought to be because women who deliver at home, do not benefit from the vaccines administered to the child at birth, including counseling and vaccination planning. Indeed, mothers who deliver in a health facility, can discuss with health professionals about vaccines and vaccine-preventable diseases, their importance, timing of vaccine initiation, completion and possible side effects associated with the vaccine during follow-up. This information may have motivated mothers to vaccinate their children and also motivate other mothers to use health facility services [ 19 ]. In forgotten communities, a context-specific approach, such as setting up micro-health facilities or working with traditional birth attendants to identify, monitor and vaccinate children from birth, will significantly improve vaccination coverage and the fight against vaccine-preventable diseases. While the idea of a beneficial effect of health personnel's recommendation on child vaccination is not shared by several authors [ 23 ], [ 24 ] our study, in agreement with the conclusions of [ 25 ], shows on the contrary that children of mothers/guardians who do not tend to act according to health personnel's recommendations on vaccination run 17,490 [7,672 − 39,872] times the risk of being zero dose. Our results corroborate those of Crocker-Buque et al., [ 26 ] who also found that the perception that a health professional's recommendation on childhood vaccination is an important factor in decision-making regarding compliance with the vaccination schedule ( ORa = 7.852[5.606–10.997]). This result prompts us to quickly understand the important informational role that general practitioners and other health professionals can play in raising awareness about the acceptability of Covid-19 vaccination. Our results are in line with a study conducted in China where health professional recommendations were identified as having an important influence on vaccination decisions, both among parents for childhood vaccination, and among adolescents or adults for influenza vaccination [ 27 ] Conclusion Although the proportion of zero-dose children found in our setting is lower than that reported at the national level, upstream and downstream interventions must be planned to reduce not only the proportion of zero-dose children but also under-vaccinated children. However, the study established a link between being a zero-dose child and the mother's age less than or equal to 19 years, the mother's low education level, the mother's "unmarried" status, the mother's occupation "worker", the child's home birth, the perception that vaccination does not protect the child against diseases as well as the failure to consider the health personnel's recommendation on child vaccination. Therefore, the study highlights the need to develop context-specific approaches to vaccinate children in difficult-to-access localities (special strategy). The results of the study also reaffirm the importance of AVS and the involvement of technical and financial partners for the identification and recovery of zero dose (ZD), under-vaccinated (SV) and unvaccinated (NV) children. Declarations Conflicts of interest The authors declare no conflict of interest. State of knowledge on the subject Although the proportion of zero-dose children is considered a major public health problem in the Democratic Republic of Congo, there has been a lack of information on the determinants of zero-dose children in the Kamina health zone in the scientific literature. Contribution of our study to knowledge This study provides an overview of the proportion of zero-dose children in the Kamina Health Zone, Haut-Lomami province in the Democratic Republic of Congo; The study highlights the need to promote female education, deliveries in health facilities, communication activities and community engagement in favor of vaccination to reduce the frequency of zero-dose children. Authors' contributions François Kalenga Luhembwe, Michel Kabamba Nzaji, Bertin Mindje Kolomba, and Patrice Nsenga Kimankinda designed this study; data collection and analysis were performed by Tristan Ilunga Kabale, Patient Ngoy Kitamba, Cécile Ngoy Kisula, and François Kalenga Luhembwe. Results interpretation and writing of the article were performed by John Ngoy Lumbule, Patrice Nsenga Kimankinda, François Kalenga Luhembwe, and Michel Kabamba Nzaji. All authors read and approved the final version of the manuscript. References WHO, “Immunization Coverage.” Accessed: Dec. 22, 2024. [Online]. Available: https://www.who.int/fr/news-room/fact-sheets/detail/immunization-coverage AN Chard et al. , “Systematic Vaccination Coverage,” Wkly. Epidemiol. Rec. , no. 46, pp. 557–572, 2020. Z. Mansour et al. , “Impact of COVID-19 pandemic on the utilization of routine immunization services in Lebanon,” PLoS One , vol. 16, no. 2, p. e0246951, Feb. 2021, doi: 10.1371/journal.pone.0246951. WHO, “Africa must vaccinate 33 million children to regain progress | WHO | Regional Office for Africa.” Accessed: Dec. 22, 2024. [Online]. Available: https://www.afro.who.int/fr/news/lafrique-doit-vacciner-33-millions-denfants-pour-renouer-avec-les-progres Unicef, “In Africa, 12.7 million children have not received one or more vaccines in the last 3 years - UNICEF.” Accessed: Dec. 22, 2024. [Online]. Available: https://www.unicef.fr/article/en-afrique-127-millions-denfants-nont-pas-recu-un-ou-plusieurs-vaccins-au-cours-des-3-dernieres-annees/ EDS, “Congo, Dem. Rep. - Demographic and Health Survey 2007,” pp. 1–13, 2007. EDS, “Democratic Republic of Congo Demographic and Health Survey 2013-2014 Preliminary Report Ministry of Planning and Monitoring of the Implementation of the Revolution of Modernity and Ministry of Public Health,” 2013, [Online]. Available: www.DHSprogram.com. MICS, “Multiple Indicator Cluster Survey with Malaria Component,” p. 601, 2018. Santetropicale/DRC, “Polio-DRC: 780,000 “zero dose” children per year - Tropical health press review.” Accessed: Dec. 22, 2024. [Online]. Available: https://www.santetropicale.com/sites_pays/actus.asp?id=33864&action=lire&rep=rdc KMZ Albert KALEMBA NGALAMULUME, Louise KAPINGA BANAYI, Bob SENKER NDIMBA, “Explanatory Factors for Low Vaccination Coverage in Children Aged 0 to 11 Months in the Luiza Zs, DRC: Risks and Perception of Mothers.”, Int. J. Soc. Sci. Sci. Stud. , 2022. Lusamba Dikassa et al., “VACCINATION COVERAGE SURVEY AMONG CHILDREN AGED 6-23 MONTHS in the Democratic Republic of Congo,” Off. site l'Ecole Santé publique Kinshsa , 2021, [Online]. Available: https://espkinshasa.net/download/10418/ BCZS/Kamina, “Mask_October 31-November 3, 2024_AVS_Polio Response_ZS_Kamina (4),” 2024. LD Brown, TT Cai, and A. DasGupta, “Interval Estimation for a Binomial Proportion,” Stat. Sci. , flight. 16, no. 2, May 2001, doi: 10.1214/ss/1009213286. DK Ishoso et al. , “‘Zero Dose’ Children in the Democratic Republic of the Congo: How Many and Who Are They?,” Vaccines , vol. 11, no. 5, p. 900, Apr. 2023, doi: 10.3390/vaccines11050900. AM Abebe, T. Mengistu, and AD Mekuria, “Measles cases, immunization coverage and its determining factors among 12–23 month children, in Bassona Worena Woreda, Amhara Region, Ethiopia, 2018,” BMC Res. Notes , vol. 12, no. 1, p. 71, Dec. 2019, doi: 10.1186/s13104-019-4104-8. AN Mohamud, A. Feleke, W. Worku, M. Kifle, and HR Sharma, “Immunization coverage of 12–23 months old children and associated factors in Jigjiga District, Somali National Regional State, Ethiopia,” BMC Public Health , vol. 14, no. 1, p. 865, Dec. 2014, doi: 10.1186/1471-2458-14-865. E. Kiptoo, “Factors Influencing Low Immunization Coverage Among Children Between 12 - 23 Months in East Pokot, Baringo Country, Kenya,” Int. J. Vaccines Vaccine. , flight. 1, no. 2, Nov. 2015, doi: 10.15406/ijvv.2015.01.00012. S. Gidado et al. , “Determinants of routine immunization coverage in Bungudu, Zamfara State, Northern Nigeria, May 2010,” Pan Afr. Med. J. , vol. 18, 2014, doi: 10.11604/pamj.supp.2014.18.1.4149. OO Odusanya, EF Alufohai, FP Meurice, and VI Ahonkhai, “Determinants of vaccination coverage in rural Nigeria,” BMC Public Health , vol. 8, no. 1, p. 381, Dec. 2008, doi: 10.1186/1471-2458-8-381. CE Ozigbu, B. Olatosi, Z. Li, JW Hardin, and NL Hair, “Correlates of Zero-Dose Vaccination Status among Children Aged 12–59 Months in Sub-Saharan Africa: A Multilevel Analysis of Individual and Contextual Factors,” Vaccines , vol. 10, no. 7, p. 1052, Jun. 2022, doi: 10.3390/vaccines10071052. TM Santos et al. , “Religious affiliation as a driver of immunization coverage: Analyzes of zero-dose vaccine prevalence in 66 low- and middle-income countries,” Front. Public Heal. , flight. 10, Oct. 2022, doi: 10.3389/fpubh.2022.977512. SC Nchinjoh et al. , “Factors Associated with Zero-Dose Childhood Vaccination Status in a Remote Fishing Community in Cameroon: A Cross-Sectional Analytical Study.,” Vaccines , vol. 10, no. 12, Nov. 2022, doi: 10.3390/vaccines10122052. AN Chard, M. Gacic-Dobo, MS Diallo, SV Sodha, and AS Wallace, “Routine Vaccination Coverage — Worldwide, 2019,” MMWR. Morb. Deadly. Wkly. Rep. , flight. 69, no. 45, pp. 1706–1710, Nov. 2020, doi: 10.15585/mmwr.mm6945a7. J. Ateudjieu et al. , “EPI immunization coverage, timeliness and dropout rate among children in a West Cameroon health district: a cross sectional study,” BMC Public Health , vol. 20, no. 1, p. 228, Dec. 2020, doi: 10.1186/s12889-020-8340-6. MK Mutua, SF Mohamed, JM Porth, and CM Faye, “Inequities in On-Time Childhood Vaccination: Evidence From Sub-Saharan Africa,” Am. J. Prev. Med. , flight. 60, no. 1, pp. S11–S23, Jan. 2021, doi: 10.1016/j.amepre.2020.10.002. T. Crocker-Buque, G. Mindra, R. Duncan, and S. Mounier-Jack, “Immunization, urbanization and slums – a systematic review of factors and interventions,” BMC Public Health , vol. 17, no. 1, p. 556, Dec. 2017, doi: 10.1186/s12889-017-4473-7. X. Jiang, X. Shang, J. Lin, Y. Zhao, W. Wang, and Y. Qiu, “Impacts of free vaccination policy and associated factors on influenza vaccination behavior of the elderly in China: A quasi-experimental study,” Vaccine , vol. 39, no. 5, pp. 846–852, Jan. 2021, doi: 10.1016/j.vaccine.2020.12.040. Tables Tables 1 to 3 are available in the Supplementary Files section. Additional Declarations The authors declare no competing interests. Supplementary Files Table1.docx Table2.docx Table3.docx Cite Share Download PDF Status: Posted Version 1 posted 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-7158136","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":487479643,"identity":"0007437f-8441-4d55-9c4c-5624594f9c0a","order_by":0,"name":"François Kalenga Luhembwe","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABCElEQVRIiWNgGAWjYBAC9gYwJQGEzCCmDRCDGAdwa+E5ANfCCNKSxsDAxkiUFgaYlsNEaJE+/OzBjwoLe8n2g42PC36dlzO439j44MMZBnl+Mez6ePjSzA17zkgkzuZJbDae2Xfb2OAYY7PhjBsMhjNnJ2DVYs/DYCbN2CaRIMeQ2CbN23M7ccMxxjZpng8MCQa3sWvh4WH/BtJiL8f/sP03b885YrTwgG1hnC2R2MbM8+MAVMsNvFrKJEF+mTnjYbM0b0OyseSxRKBfzkjg9AvQYdskflTU2UucTz74meePnRzf4cMHH3w4ZiPPL41dCypgbIMzJYhQDgZ/iFU4CkbBKBgFIwkAACr0XQg7RfN/AAAAAElFTkSuQmCC","orcid":"https://orcid.org/0009-0006-3161-4963","institution":"Université de Kamina","correspondingAuthor":true,"prefix":"","firstName":"François","middleName":"Kalenga","lastName":"Luhembwe","suffix":""},{"id":487479644,"identity":"5bcfb135-2d9f-4409-bc84-d291fbe528f2","order_by":1,"name":"Bertin Mindje Kolomba","email":"","orcid":"","institution":"Université de Kamina","correspondingAuthor":false,"prefix":"","firstName":"Bertin","middleName":"Mindje","lastName":"Kolomba","suffix":""},{"id":487479645,"identity":"f7529bc5-a4b2-436c-9f3d-7a310946d6a0","order_by":2,"name":"Tristan Ilunga Kabale","email":"","orcid":"","institution":"Université de Kamina","correspondingAuthor":false,"prefix":"","firstName":"Tristan","middleName":"Ilunga","lastName":"Kabale","suffix":""},{"id":487479646,"identity":"023769aa-838d-4a1a-a83e-868e7ba238d6","order_by":3,"name":"Cécile Ngoy Kisula","email":"","orcid":"","institution":"Université de Kamina","correspondingAuthor":false,"prefix":"","firstName":"Cécile","middleName":"Ngoy","lastName":"Kisula","suffix":""},{"id":487479647,"identity":"ad3c1fb5-e82b-48be-83aa-1c39206737d4","order_by":4,"name":"Patrice Nsenga Kimankinda","email":"","orcid":"","institution":"Université de Kamina","correspondingAuthor":false,"prefix":"","firstName":"Patrice","middleName":"Nsenga","lastName":"Kimankinda","suffix":""},{"id":487479648,"identity":"8a473598-4899-48f7-a19d-b7ab8e476e60","order_by":5,"name":"Patient Ngoy Kitamba","email":"","orcid":"","institution":"Université de Kamina","correspondingAuthor":false,"prefix":"","firstName":"Patient","middleName":"Ngoy","lastName":"Kitamba","suffix":""},{"id":487479649,"identity":"88f231c6-c4bb-4b2d-8ecf-1852d27cedd3","order_by":6,"name":"John Ngoy Lumbule","email":"","orcid":"","institution":"Université de Kamina","correspondingAuthor":false,"prefix":"","firstName":"John","middleName":"Ngoy","lastName":"Lumbule","suffix":""},{"id":487479650,"identity":"a8cb0352-0450-4aa5-9490-a560449f0c6b","order_by":7,"name":"Michel Kabamba Nzaji","email":"","orcid":"","institution":"Université de Kamina","correspondingAuthor":false,"prefix":"","firstName":"Michel","middleName":"Kabamba","lastName":"Nzaji","suffix":""}],"badges":[],"createdAt":"2025-07-18 13:25:31","currentVersionCode":1,"declarations":{"humanSubjects":true,"vertebrateSubjects":true,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":true,"humanSubjectConsent":true,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":true},"doi":"10.21203/rs.3.rs-7158136/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7158136/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":87187471,"identity":"e16631c8-e960-400b-89e0-97d881d9ba0e","added_by":"auto","created_at":"2025-07-21 10:41:34","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":623580,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7158136/v1/9769dba1-65ab-44b3-bbca-030101207d7c.pdf"},{"id":87186850,"identity":"a9152db3-81e9-4ac8-a33c-dfe125ed4249","added_by":"auto","created_at":"2025-07-21 10:33:34","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":11479,"visible":true,"origin":"","legend":"","description":"","filename":"Table1.docx","url":"https://assets-eu.researchsquare.com/files/rs-7158136/v1/a4a559bf99e44760012009f7.docx"},{"id":87186411,"identity":"ae16f097-276d-4569-8cb2-bc9a0d2d0add","added_by":"auto","created_at":"2025-07-21 10:25:34","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":12741,"visible":true,"origin":"","legend":"","description":"","filename":"Table2.docx","url":"https://assets-eu.researchsquare.com/files/rs-7158136/v1/65009e6e504d57b9873971c1.docx"},{"id":87186417,"identity":"ee8406da-f0e7-4367-8348-4b2e9dcf62d7","added_by":"auto","created_at":"2025-07-21 10:25:34","extension":"docx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":14060,"visible":true,"origin":"","legend":"","description":"","filename":"Table3.docx","url":"https://assets-eu.researchsquare.com/files/rs-7158136/v1/e222badf08fdb7b7d1d0a3f8.docx"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eDeterminants of zero-dose children in Kamina, DR Congo\u003c/strong\u003e\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eVaccination saves millions of lives each year and is widely recognized as one of the most effective health interventions in the world. Yet, over the past decade, childhood vaccination coverage rates have plateaued at around 85%, leaving millions of children vulnerable to life-threatening diseases that vaccines can prevent. This plateau is deflecting the world from its goal of providing access to safe and effective medicines and vaccines for all, as outlined in the World Health Organization's 2030 Agenda for Immunization and the United Nations 2030 Agenda for Sustainable Development [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e] .\u003c/p\u003e\u003cp\u003eGlobally, an estimated 21.8\u0026nbsp;million infants remain missing from routine immunization services. Of the 19.7\u0026nbsp;million children worldwide who did not receive all three doses of diphtheria, tetanus, and pertussis (DTP) vaccine in 2019, 13.8\u0026nbsp;million (70%) were zero-dose children [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. This figure has increased sharply following the sudden onset of the COVID-19 pandemic, which has significantly disrupted essential lifesaving services such as routine immunization (RSV), increasing countries' vulnerability to outbreaks of vaccine-preventable diseases (VPDs) [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e] .\u003c/p\u003e\u003cp\u003eIn Africa, approximately 33\u0026nbsp;million children will need to be vaccinated between 2023 and 2025 for the continent to meet the 2030 global immunization targets, including reducing morbidity and mortality from vaccine-preventable diseases, according to an analysis by the World Health Organization (WHO). The unprecedented impact of the COVID-19 pandemic on routine immunization services has led to an increase in the number of zero-dose and under-immunized children, a 16% increase between 2019 and 2021, bringing the cumulative total of these children (over the period 2019–2021) to approximately 33\u0026nbsp;million, representing almost half of the global number [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] .\u003c/p\u003e\u003cp\u003eAccording to the UNICEF report, Africa is the region with the largest number of zero-dose or under-vaccinated children: 12.7\u0026nbsp;million children were under-vaccinated in 2021 and 8.7\u0026nbsp;million children had a zero-dose vaccination status. Half of the top 20 countries in the world with the largest number of zero-dose children are in Africa. Nigeria and Ethiopia are the two countries on the continent with the largest number of zero-dose children, with more than 2.2\u0026nbsp;million and 1.1\u0026nbsp;million children respectively. Two out of five zero-dose children in Africa live in one of these two countries [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] .\u003c/p\u003e\u003cp\u003eIn the Democratic Republic of Congo (DRC), despite progress in reducing under-five mortality, which fell from 158 per 1000 live births in 2007 [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] to 104 per 1000 live births in 2013 [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], and to 70 per 1000 live births in 2017 [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. This excess mortality among children is largely attributable to vaccine-preventable diseases. In 2013, vaccination coverage estimates based on vaccination card information showed that only 41% of children aged 12 to 23 months had been fully vaccinated before the age of 12 months in the DRC. When information provided by the mother was taken into account, this percentage increased to 45% [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] .\u003c/p\u003e\u003cp\u003eEach year, the DRC records seven hundred and eighty thousand (780,000) zero-dose children, while in 2022, 1.5\u0026nbsp;million children were insufficiently vaccinated. One in five (5), or 19%, is zero-dose, one in three (3) is insufficiently vaccinated and two (2) in five (5) have not received the three doses of DTP (diphtheria, tetanus, pertussis). Two-thirds (2/3) of zero-dose children come from the most central and rural areas of 10 of the country's 26 provinces. Among these 2/3 children, 75% live less than one kilometer from a health facility, while 90% are less than three kilometers away [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] .\u003c/p\u003e\u003cp\u003eNumerous studies have been conducted in the Democratic Republic of Congo to identify factors associated with incomplete vaccination and low vaccination coverage [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. However, few of them have been conducted on zero-dose children. It is in this context that this study was conducted to determine the proportion and identify the determinants of zero-dose children in Kamina.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cb\u003eStudy framework\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThis study was conducted in the town of Kamina located in the Haut-Lomami Province in the Democratic Republic of Congo. The town of Kamina, capital of the Haut-Lomami province, is a decentralized administrative entity, with an estimated population of 366,557 inhabitants spread across sixteen districts. Its population 's main occupations are agriculture and small businesses. The main agricultural products are: corn, beans, sweet potatoes, peanuts. The population of children aged 12 to 23 months, the target of the PEV, is 35,595 [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] .\u003c/p\u003e\u003cp\u003e\u003cb\u003eType, period and study population\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThis is an observational study of a cross-sectional analytical type conducted between March 2024 and January 2025. The survey generally covered all households in the RVA, Urban Center, Kyabukwa, Katuba I, and Katuba IV health areas. The source population included households in all avenues of these selected health areas. The statistical units were children aged 12 to 23 months, and the responding units consisted of the mothers or guardians of these children.\u003c/p\u003e\u003cp\u003e\u003cb\u003eSample and sampling\u003c/b\u003e\u003c/p\u003e\u003cp\u003eA sample of 236 study participants was calculated at a specified 95% confidence interval and an acceptable margin of error of 5% (0.05). A national proportion of 0.19 or 19% of zero-dose children [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] was used in this study. This sample was calculated using the formula of Brown \u003cem\u003eet al\u003c/em\u003e. [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. The selection of statistical units was done using three (3) stage probability sampling.\u003c/p\u003e\u003cp\u003e\u003cb\u003eData collection tools and techniques\u003c/b\u003e\u003c/p\u003e\u003cp\u003eUsing a previously tested electronic questionnaire configured on the SurveyCTO Collect tool, mothers or caregivers were interviewed about the vaccines received by the child before twelve (12) months. The information collected included socio-demographic characteristics, factors related to the vaccination system and the mothers' knowledge, attitudes and practices on vaccination. The vaccines received by the child were obtained from the vaccination card.\u003c/p\u003e\u003cp\u003e\u003cb\u003eEthical considerations\u003c/b\u003e\u003c/p\u003e\u003cp\u003eEthical clearance was obtained from the Ethics Committee of the School of Public Health (Approval Letter No. UNILU/CEM/229/2024), the University of Lubumbashi, and the DRC, in accordance with the Declaration of Helsinki. Participants were informed that their participation was voluntary. Verbal and informed consent was obtained from each study participant, which was approved by the Ethics Committee.\u003c/p\u003e\u003cp\u003e\u003cb\u003eProcessing and analysis of statistical data\u003c/b\u003e\u003c/p\u003e\u003cp\u003eData were analyzed using IBM SPSS 26 and Jamovi version 2.5.5 software. Input checks allowed us to minimize errors. Cronbach's alpha coefficient allowed us to measure the internal consistency or reliability of our data. We performed weighted flat sorting analyses of sociodemographic characteristics in the study sample with categorical variables reported as frequencies and percentages, where appropriate, and continuous variables summarized using means and standard deviations or medians and interquartile ranges, depending on the normality of the distribution using the Kolmogorov-Smirnov test. In the bivariate analysis, associations between the dependent variable and the independent variables were tested using the Pearson chi-square or Fischer exact test as appropriate. The odds ratio and its 95% confidence interval were calculated to measure the association between random variables. Analysis of factors associated with zero-dose children was performed using a multivariate logistic regression model of the “Wald Ascending” type. The Archer-Lemeshow test was used to assess the goodness of fit of the logistic regression model. The model performance was assessed using ROC analysis, which was considered acceptable after checking the AUC.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eProportion of zero-dose children and sociodemographic characteristics \u003c/strong\u003e\u003cstrong\u003e: \u003c/strong\u003eThe results of this study show that the proportion of zero-dose children in our environment is 18.2%. The majority of mothers who participated in this study, 87.7%, were over 19 years old, 73.3% had a low level of education (none/primary), 97.0% were married, 90.7% were Christian, 83.5% were housewives or had a liberal activity. In relation to the child\u0026apos;s place of birth, 3.4% of children were born at home ( \u003cstrong\u003eTable 1 \u003c/strong\u003e).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRelationship between zero-dose vaccination status and sociodemographic characteristics \u003c/strong\u003e\u003cstrong\u003e: \u003c/strong\u003eThe results of this study highlight that the probability of having a zero-dose vaccination status is statistically very high among children of unmarried, working mothers, with a low level of education (none/primary) and whose age less than or equal to 19 years (p˂0.05). Belonging to an ancestral church increases 14.235 [5.336 - 37.973] times the risk of zero-dose children. However, children born at home are 15.486 [3.008 -79.723 ] times more likely to be zero-dose ( \u003cstrong\u003eTable 2 \u003c/strong\u003e).\u003c/p\u003e\n\u003cp\u003cstrong\u003eRelationship between zero-dose vaccination status and mother/caregiver perception of child vaccination \u003c/strong\u003e\u003cstrong\u003e: \u003c/strong\u003eThis study found that mothers or caretakers of children with a perception that vaccination according to the schedule does not protect the child against diseases are likely to have zero-dose children (p˂0.05). It should also be noted that children of mothers/caregivers who do not tend to act according to the recommendations of a health worker on vaccination run 17,490 [7,672 - 39,872] times the risk of being zero-dose ( \u003cstrong\u003eTable 3 \u003c/strong\u003e).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLogistic regression of the different determinants of zero-dose children \u003c/strong\u003e\u003cstrong\u003e: \u003c/strong\u003eThis study indicates that the determinants of zero-dose children in our environment are the mother\u0026apos;s age less than or equal to 19 years (ORa= 10.996 [ 3.035 - 39.840 ]) , the mother\u0026apos;s low level of education (ORa= 16.763 [ 2.230 - 125.991 ]) , the mother\u0026apos;s \u0026quot;unmarried\u0026quot; status (ORa= 16.436 [ 1.311 - 206.053 ]) , the mother\u0026apos;s occupation \u0026quot;worker\u0026quot; (ORa= 86.163 [ 12.839 - 578.252 ]) , the child\u0026apos;s birth at home (ORa= 4.950 [ 1.127 - 21.748 ]) , having a perception according to which vaccination does not protect the child against diseases (ORa = 8.441 [ 2.385 - 29.872 ]) as well as the non-consideration of the recommendation of health personnel on the vaccination of the child (OR = 4.388 [ 1.254 - 15.354 ]) ( \u003cstrong\u003eTable 4 \u003c/strong\u003e).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eROC curve of determinants of zero-dose children \u003c/strong\u003e\u003cstrong\u003e: \u003c/strong\u003eDiscriminant factor analysis shows that the area under the curve (AUC) values in ( \u003cstrong\u003eFigure 1 \u003c/strong\u003e) indicate a predictive capacity on zero-dose vaccination status of 0.919 or 91.9% (AUC between 0.857 and 0.981).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur study, one of the first of its kind in the Haut-Lomami province, reported a proportion of zero-dose children of 18.2%. This result, lower than that of 19.1% reported by Ishoso et al. [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], shows an improvement in vaccination coverage in our setting given that WHO and UNICEF have noted an increase in the prevalence of zero-dose children in sub-Saharan Africa from 6.8% in 2010 to 14% during the year of the COVID-19 pandemic of 2021 [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. These results prove that the proportion of zero-dose children varies considerably between and within countries, with substantial heterogeneities in context. These results therefore highlight the variability of the proportion of zero children, both geographically and in terms of population characteristics, demonstrating the need for vaccination strategies appropriate to each country and each area, which take into account the size of the country, the available resources and the context in which the populations live.\u003c/p\u003e\u003cp\u003eIn this study, the probability of having a zero-dose vaccination status was statistically very high among children of mothers whose age was less than or equal to 19 years (p˂0.05). This result is consistent with a study conducted in Ethiopia [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. According to several studies, the older the mother, the less hesitant and less obstacles she may encounter in getting her child vaccinated [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. According to Ishoso et al., the young age of the mother is a significant factor in improving vaccination coverage [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] .\u003c/p\u003e\u003cp\u003eThe study found that low maternal education (none/primary) had a statistically significant association with the child's zero-dose vaccination status. The lower the maternal education, the greater the likelihood of being zero-dose. Numerous studies on full vaccination coverage of children aged 12 to 23 months and reasons for non-vaccination in peri-urban areas have also found the same result. [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Indeed, maternal education level has been associated with vaccination in most settings [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. According to the results reported by Mohamud et al., literate mothers were 3.06 times more likely to fully vaccinate their children than illiterate mothers (AOR\u0026thinsp;=\u0026thinsp;3.06, 95% CI\u0026thinsp;=\u0026thinsp;1.64, 5.71) [ 16]. In other similar studies, maternal education level has been reported as a predictor of zero-dose children [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. This may be because literate mothers have better knowledge of vaccine-preventable diseases and recognize the importance of vaccination.\u003c/p\u003e\u003cp\u003eConsistent with studies conducted in Ethiopia by Abebe et al., [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], the present study also found that ancestral church affiliation increases the risk of zero-dose children 14,235 [5,336\u0026thinsp;\u0026minus;\u0026thinsp;37,973] times. In contrast to the Demographic and Health Surveys conducted by Ozigbu et al., in 33 sub-Saharan African countries, children of Muslims were significantly more likely to be zero-dose than children of Christians (25.2% vs. 12.3%) [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. However, Santos et al., in an analysis of 66 low- and middle-income countries that have conducted standardized national surveys since 2010, found that the relationship between religion and vaccination was not consistent across the world [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. The latter hypothesis suggests that various cultural and community factors may modulate the relationship between religious affiliation and vaccination [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Collaboration with religious leaders may be an appropriate solution.\u003c/p\u003e\u003cp\u003eOur results, like those of Nchinjoh et al. [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e] showed that children born at home are 15,486 [3,008\u0026ndash;79,723] times more likely to be zero dose. This statistical difference is thought to be because women who deliver at home, do not benefit from the vaccines administered to the child at birth, including counseling and vaccination planning. Indeed, mothers who deliver in a health facility, can discuss with health professionals about vaccines and vaccine-preventable diseases, their importance, timing of vaccine initiation, completion and possible side effects associated with the vaccine during follow-up. This information may have motivated mothers to vaccinate their children and also motivate other mothers to use health facility services [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. In forgotten communities, a context-specific approach, such as setting up micro-health facilities or working with traditional birth attendants to identify, monitor and vaccinate children from birth, will significantly improve vaccination coverage and the fight against vaccine-preventable diseases.\u003c/p\u003e\u003cp\u003eWhile the idea of a beneficial effect of health personnel's recommendation on child vaccination is not shared by several authors [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e] our study, in agreement with the conclusions of [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e], shows on the contrary that children of mothers/guardians who do not tend to act according to health personnel's recommendations on vaccination run 17,490 [7,672\u0026thinsp;\u0026minus;\u0026thinsp;39,872] times the risk of being zero dose. Our results corroborate those of Crocker-Buque et al., [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e] who also found that the perception that a health professional's recommendation on childhood vaccination is an important factor in decision-making regarding compliance with the vaccination schedule ( ORa\u0026thinsp;=\u0026thinsp;7.852[5.606\u0026ndash;10.997]). This result prompts us to quickly understand the important informational role that general practitioners and other health professionals can play in raising awareness about the acceptability of Covid-19 vaccination. Our results are in line with a study conducted in China where health professional recommendations were identified as having an important influence on vaccination decisions, both among parents for childhood vaccination, and among adolescents or adults for influenza vaccination [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eAlthough the proportion of zero-dose children found in our setting is lower than that reported at the national level, upstream and downstream interventions must be planned to reduce not only the proportion of zero-dose children but also under-vaccinated children. However, the study established a link between being a zero-dose child and the mother's age less than or equal to 19 years, the mother's low education level, the mother's \"unmarried\" status, the mother's occupation \"worker\", the child's home birth, the perception that vaccination does not protect the child against diseases as well as the failure to consider the health personnel's recommendation on child vaccination. Therefore, the study highlights the need to develop context-specific approaches to vaccinate children in difficult-to-access localities (special strategy). The results of the study also reaffirm the importance of AVS and the involvement of technical and financial partners for the identification and recovery of zero dose (ZD), under-vaccinated (SV) and unvaccinated (NV) children.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConflicts of interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eState of knowledge on the subject\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAlthough the proportion of zero-dose children is considered a major public health problem in the Democratic Republic of Congo, there has been a lack of information on the determinants of zero-dose children in the Kamina health zone in the scientific literature.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eContribution of our study to knowledge\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eThis study provides an overview of the proportion of zero-dose children in the Kamina Health Zone, Haut-Lomami province in the Democratic Republic of Congo;\u003c/li\u003e\n \u003cli\u003eThe study highlights the need to promote female education, deliveries in health facilities, communication activities and community engagement in favor of vaccination to reduce the frequency of zero-dose children.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFran\u0026ccedil;ois Kalenga Luhembwe, Michel Kabamba Nzaji, Bertin Mindje Kolomba, and Patrice Nsenga Kimankinda designed this study; data collection and analysis were performed by Tristan Ilunga Kabale, Patient Ngoy Kitamba, C\u0026eacute;cile Ngoy Kisula, and Fran\u0026ccedil;ois Kalenga Luhembwe. Results interpretation and writing of the article were performed by John Ngoy Lumbule, Patrice Nsenga Kimankinda, Fran\u0026ccedil;ois Kalenga Luhembwe, and Michel Kabamba Nzaji. All authors read and approved the final version of the manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eWHO, \u0026ldquo;Immunization Coverage.\u0026rdquo; Accessed: Dec. 22, 2024. [Online]. Available: https://www.who.int/fr/news-room/fact-sheets/detail/immunization-coverage\u003c/li\u003e\n\u003cli\u003eAN Chard \u003cem\u003eet al. \u003c/em\u003e, \u0026ldquo;Systematic Vaccination Coverage,\u0026rdquo; \u003cem\u003eWkly. Epidemiol. Rec. \u003c/em\u003e, no. 46, pp. 557\u0026ndash;572, 2020.\u003c/li\u003e\n\u003cli\u003eZ. Mansour \u003cem\u003eet al. \u003c/em\u003e, \u0026ldquo;Impact of COVID-19 pandemic on the utilization of routine immunization services in Lebanon,\u0026rdquo; \u003cem\u003ePLoS One \u003c/em\u003e, vol. 16, no. 2, p. e0246951, Feb. 2021, doi: 10.1371/journal.pone.0246951.\u003c/li\u003e\n\u003cli\u003eWHO, \u0026ldquo;Africa must vaccinate 33 million children to regain progress | WHO | Regional Office for Africa.\u0026rdquo; Accessed: Dec. 22, 2024. [Online]. Available: https://www.afro.who.int/fr/news/lafrique-doit-vacciner-33-millions-denfants-pour-renouer-avec-les-progres\u003c/li\u003e\n\u003cli\u003eUnicef, \u0026ldquo;In Africa, 12.7 million children have not received one or more vaccines in the last 3 years - UNICEF.\u0026rdquo; Accessed: Dec. 22, 2024. [Online]. Available: https://www.unicef.fr/article/en-afrique-127-millions-denfants-nont-pas-recu-un-ou-plusieurs-vaccins-au-cours-des-3-dernieres-annees/\u003c/li\u003e\n\u003cli\u003eEDS, \u0026ldquo;Congo, Dem. Rep. - Demographic and Health Survey 2007,\u0026rdquo; pp. 1\u0026ndash;13, 2007.\u003c/li\u003e\n\u003cli\u003eEDS, \u0026ldquo;Democratic Republic of Congo Demographic and Health Survey 2013-2014 Preliminary Report Ministry of Planning and Monitoring of the Implementation of the Revolution of Modernity and Ministry of Public Health,\u0026rdquo; 2013, [Online]. Available: www.DHSprogram.com.\u003c/li\u003e\n\u003cli\u003eMICS, \u0026ldquo;Multiple Indicator Cluster Survey with Malaria Component,\u0026rdquo; p. 601, 2018.\u003c/li\u003e\n\u003cli\u003eSantetropicale/DRC, \u0026ldquo;Polio-DRC: 780,000 \u0026ldquo;zero dose\u0026rdquo; children per year - Tropical health press review.\u0026rdquo; Accessed: Dec. 22, 2024. [Online]. Available: https://www.santetropicale.com/sites_pays/actus.asp?id=33864\u0026amp;action=lire\u0026amp;rep=rdc\u003c/li\u003e\n\u003cli\u003eKMZ Albert KALEMBA NGALAMULUME, Louise KAPINGA BANAYI, Bob SENKER NDIMBA, \u0026ldquo;Explanatory Factors for Low Vaccination Coverage in Children Aged 0 to 11 Months in the Luiza Zs, DRC: Risks and Perception of Mothers.\u0026rdquo;, \u003cem\u003eInt. J. Soc. Sci. Sci. Stud. \u003c/em\u003e, 2022.\u003c/li\u003e\n\u003cli\u003eLusamba Dikassa et al., \u0026ldquo;VACCINATION COVERAGE SURVEY AMONG CHILDREN AGED 6-23 MONTHS in the Democratic Republic of Congo,\u0026rdquo; \u003cem\u003eOff. site l\u0026apos;Ecole Sant\u0026eacute; publique Kinshsa \u003c/em\u003e, 2021, [Online]. Available: https://espkinshasa.net/download/10418/\u003c/li\u003e\n\u003cli\u003eBCZS/Kamina, \u0026ldquo;Mask_October 31-November 3, 2024_AVS_Polio Response_ZS_Kamina (4),\u0026rdquo; 2024.\u003c/li\u003e\n\u003cli\u003eLD Brown, TT Cai, and A. DasGupta, \u0026ldquo;Interval Estimation for a Binomial Proportion,\u0026rdquo; \u003cem\u003eStat. Sci. \u003c/em\u003e, flight. 16, no. 2, May 2001, doi: 10.1214/ss/1009213286.\u003c/li\u003e\n\u003cli\u003eDK Ishoso \u003cem\u003eet al. \u003c/em\u003e, \u0026ldquo;\u0026lsquo;Zero Dose\u0026rsquo; Children in the Democratic Republic of the Congo: How Many and Who Are They?,\u0026rdquo; \u003cem\u003eVaccines \u003c/em\u003e, vol. 11, no. 5, p. 900, Apr. 2023, doi: 10.3390/vaccines11050900.\u003c/li\u003e\n\u003cli\u003eAM Abebe, T. Mengistu, and AD Mekuria, \u0026ldquo;Measles cases, immunization coverage and its determining factors among 12\u0026ndash;23 month children, in Bassona Worena Woreda, Amhara Region, Ethiopia, 2018,\u0026rdquo; \u003cem\u003eBMC Res. Notes \u003c/em\u003e, vol. 12, no. 1, p. 71, Dec. 2019, doi: 10.1186/s13104-019-4104-8.\u003c/li\u003e\n\u003cli\u003eAN Mohamud, A. Feleke, W. Worku, M. Kifle, and HR Sharma, \u0026ldquo;Immunization coverage of 12\u0026ndash;23 months old children and associated factors in Jigjiga District, Somali National Regional State, Ethiopia,\u0026rdquo; \u003cem\u003eBMC Public Health \u003c/em\u003e, vol. 14, no. 1, p. 865, Dec. 2014, doi: 10.1186/1471-2458-14-865.\u003c/li\u003e\n\u003cli\u003eE. Kiptoo, \u0026ldquo;Factors Influencing Low Immunization Coverage Among Children Between 12 - 23 Months in East Pokot, Baringo Country, Kenya,\u0026rdquo; \u003cem\u003eInt. J. Vaccines Vaccine. \u003c/em\u003e, flight. 1, no. 2, Nov. 2015, doi: 10.15406/ijvv.2015.01.00012.\u003c/li\u003e\n\u003cli\u003eS. Gidado \u003cem\u003eet al. \u003c/em\u003e, \u0026ldquo;Determinants of routine immunization coverage in Bungudu, Zamfara State, Northern Nigeria, May 2010,\u0026rdquo; \u003cem\u003ePan Afr. Med. J. \u003c/em\u003e, vol. 18, 2014, doi: 10.11604/pamj.supp.2014.18.1.4149.\u003c/li\u003e\n\u003cli\u003eOO Odusanya, EF Alufohai, FP Meurice, and VI Ahonkhai, \u0026ldquo;Determinants of vaccination coverage in rural Nigeria,\u0026rdquo; \u003cem\u003eBMC Public Health \u003c/em\u003e, vol. 8, no. 1, p. 381, Dec. 2008, doi: 10.1186/1471-2458-8-381.\u003c/li\u003e\n\u003cli\u003eCE Ozigbu, B. Olatosi, Z. Li, JW Hardin, and NL Hair, \u0026ldquo;Correlates of Zero-Dose Vaccination Status among Children Aged 12\u0026ndash;59 Months in Sub-Saharan Africa: A Multilevel Analysis of Individual and Contextual Factors,\u0026rdquo; \u003cem\u003eVaccines \u003c/em\u003e, vol. 10, no. 7, p. 1052, Jun. 2022, doi: 10.3390/vaccines10071052.\u003c/li\u003e\n\u003cli\u003eTM Santos \u003cem\u003eet al. \u003c/em\u003e, \u0026ldquo;Religious affiliation as a driver of immunization coverage: Analyzes of zero-dose vaccine prevalence in 66 low- and middle-income countries,\u0026rdquo; \u003cem\u003eFront. Public Heal. \u003c/em\u003e, flight. 10, Oct. 2022, doi: 10.3389/fpubh.2022.977512.\u003c/li\u003e\n\u003cli\u003eSC Nchinjoh \u003cem\u003eet al. \u003c/em\u003e, \u0026ldquo;Factors Associated with Zero-Dose Childhood Vaccination Status in a Remote Fishing Community in Cameroon: A Cross-Sectional Analytical Study.,\u0026rdquo; \u003cem\u003eVaccines \u003c/em\u003e, vol. 10, no. 12, Nov. 2022, doi: 10.3390/vaccines10122052.\u003c/li\u003e\n\u003cli\u003eAN Chard, M. Gacic-Dobo, MS Diallo, SV Sodha, and AS Wallace, \u0026ldquo;Routine Vaccination Coverage \u0026mdash; Worldwide, 2019,\u0026rdquo; \u003cem\u003eMMWR. Morb. Deadly. Wkly. Rep. \u003c/em\u003e, flight. 69, no. 45, pp. 1706\u0026ndash;1710, Nov. 2020, doi: 10.15585/mmwr.mm6945a7.\u003c/li\u003e\n\u003cli\u003eJ. Ateudjieu \u003cem\u003eet al. \u003c/em\u003e, \u0026ldquo;EPI immunization coverage, timeliness and dropout rate among children in a West Cameroon health district: a cross sectional study,\u0026rdquo; \u003cem\u003eBMC Public Health \u003c/em\u003e, vol. 20, no. 1, p. 228, Dec. 2020, doi: 10.1186/s12889-020-8340-6.\u003c/li\u003e\n\u003cli\u003eMK Mutua, SF Mohamed, JM Porth, and CM Faye, \u0026ldquo;Inequities in On-Time Childhood Vaccination: Evidence From Sub-Saharan Africa,\u0026rdquo; \u003cem\u003eAm. J. Prev. Med. \u003c/em\u003e, flight. 60, no. 1, pp. S11\u0026ndash;S23, Jan. 2021, doi: 10.1016/j.amepre.2020.10.002.\u003c/li\u003e\n\u003cli\u003eT. Crocker-Buque, G. Mindra, R. Duncan, and S. Mounier-Jack, \u0026ldquo;Immunization, urbanization and slums \u0026ndash; a systematic review of factors and interventions,\u0026rdquo; \u003cem\u003eBMC Public Health \u003c/em\u003e, vol. 17, no. 1, p. 556, Dec. 2017, doi: 10.1186/s12889-017-4473-7.\u003c/li\u003e\n\u003cli\u003eX. Jiang, X. Shang, J. Lin, Y. Zhao, W. Wang, and Y. Qiu, \u0026ldquo;Impacts of free vaccination policy and associated factors on influenza vaccination behavior of the elderly in China: A quasi-experimental study,\u0026rdquo; \u003cem\u003eVaccine \u003c/em\u003e, vol. 39, no. 5, pp. 846\u0026ndash;852, Jan. 2021, doi: 10.1016/j.vaccine.2020.12.040.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTables 1 to 3 are available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"Université de Kamina","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"determinants, child, zero dose, Kamina, Democratic Republic of Congo","lastPublishedDoi":"10.21203/rs.3.rs-7158136/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7158136/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eIntroduction :\u003c/strong\u003e Vaccination is recognized as one of the most effective and cost-effective public health interventions. This work presents a summary of the factors that may explain the presence of zero-dose children in Congolese communities.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e This is a cross-sectional analytical study conducted between March 2024 and January 2025. The statistical units were children aged 12 to 23 months and the responding units were the mothers/guardians of these children selected through three (3) stage probability sampling. The data were collected using the SurveyCTO tool and analyzed using IBM SPSS 26 and Jamovi version 2.5.5 software. Cronbach's alpha coefficient allowed us to measure the internal consistency of the data. The associations were tested using the Pearson chi-square or Fischer exact test. The analysis of factors associated with zero-dose children was done using a multivariate logistic regression model of the \"Wald Ascending\" type. The Archer-Lemeshow test was used to assess the goodness of fit of the model and the ROC curve allowed us to evaluate the performance of the model.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults :\u003c/strong\u003e The study indicated that the determinants of zero dose children in our environment are the mother's age less than or equal to 19 years (ORa= 10.996 [ 3.035 - 39.840 ]), the mother's low education level (ORa= 16.763 [ 2.230 - 125.991 ]), the mother's \"unmarried\" status (ORa= 16.436 [ 1.311 - 206.053 ]), the mother's occupation \"worker\" (ORa= 86.163 [ 12.839 - 578.252 ]), the child's home birth (ORa= 4.950 [ 1.127 - 21.748 ]), the perception that vaccination does not protect the child against diseases (ORa= 8,441 [ 2,385 - 29,872 ]) as well as the non-consideration of the recommendation of health personnel on the vaccination of the child (OR = 4,388 [ 1,254 - 15,354 ]).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion :\u003c/strong\u003e In order to reduce the incidence of zero-dose children, the study highlights the need to promote female education, deliveries in health facilities, communication activities and community engagement in favor of vaccination.\u003c/p\u003e","manuscriptTitle":"Determinants of zero-dose children in Kamina, DR Congo","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-21 10:25:29","doi":"10.21203/rs.3.rs-7158136/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"565947f4-77dd-4cfc-96a8-374a7913b022","owner":[],"postedDate":"July 21st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":51756254,"name":"Statistical Epidemiology"}],"tags":[],"updatedAt":"2025-07-21T10:25:29+00:00","versionOfRecord":[],"versionCreatedAt":"2025-07-21 10:25:29","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7158136","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7158136","identity":"rs-7158136","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}