Mpox vaccination coverage in the Democratic Republic of Congo: A systematic review and meta-analysis of uptake and acceptance (1970–2024)

Background The Democratic Republic of Congo (DRC) is recognized as the global epicenter of human Mpox. While vaccination is crucial for outbreak prevention, especially as the disease transitions from zoonotic spillover to sustained human-to-human transmission, comprehensive assessments of vaccination coverage trends across the country are notably absent from the literature. This systematic review and meta-analysis address this gap by providing the first pooled estimate of Mpox vaccine uptake and acceptance in the DRC over a 54-year period (1970-2024). Our study captures critical transitions, including the post-smallpox eradication era and recent global outbreaks, to identify temporal trends, geographic disparities in this high-risk setting.

We conducted this review following PRISMA guidelines, systematically searching PubMed, Scopus, ScienceDirect, Web of Sciences, CINAHL, and Embase. Grey literature was also searched to ensure comprehensiveness. Using random-effects models, we calculated pooled estimates for vaccine uptake and acceptance rates, with prespecified subgroup analyses examining variations by: (1) period, (2) geographic region, and (3) type of participants. We quantified heterogeneity using I2 statistics and conducted meta-regression to identify predictors of vaccination coverage heterogeneity. A p-value ⍰ 0.05 was considered statistically significant.

Our analysis revealed a pooled Mpox vaccine uptake of 20.01% (95% CI: 7.45–43.75) with high heterogeneity (I2 = 99.4%, p < 0.001), indicating substantial variability across studies. Vaccine acceptance was higher at 54.17% (95% CI: 20.82–84.16) with high heterogeneity (I2 = 97.6%, p < 0.001). Temporal analysis showed a significant decline from 32.30% (95% CI: 14.62–57.75) coverage during 1970–2000 to 1.36% (95% CI: 0.29–6.11) in 2020–2024. Geographic disparities existed, with the Northwest regions achieving 47.11% (95% CI: 13.46–83.61) coverage compared to 5.47% (95% CI: 0.56–37.32) in Eastern conflict-affected zones. Meta-regression identified no significant predictors of coverage heterogeneity.

Despite moderate acceptance rates, actual Mpox vaccination uptake in the DRC remains critically low, with worsening coverage in recent years and substantial regional inequities. These findings underscore the urgent need for context-specific interventions to bridge the intention-action gap in this high-risk setting. Competing Interest Statement The authors have declared no competing interest. Funding Statement This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors. Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: All data sources are available in the reference list. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Footnotes Searching was conducted in additional databases. The statistics were changed to be more accurate, and the whole manuscript has been revised accordingly. Data Availability The sources of data supporting this systematic review are available in the reference. All data generated or analyzed during this study are included in this published article and supplemental material. Abbreviations - CI - Confidence interval - DRC - Democratic Republic of Congo - HCW - Healthcare worker - MeSH - Medical subject headings - Mpox - Monkeypox - PRISMA - Preferred reporting items for systematic reviews and meta-analysis