Conference Abstract | Volume 9 (ConfPro8): Abstract 08 | Published: 01 Oct 2026
Elvis Akem Tambe1,&, Florence Gyembuzie Wongnaah2
1Independent Public Health Consultant, Yaounde, Cameroon; 2Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden
&Corresponding author: Elvis Akem Tambe, Independent Public Health Consultant, Yaounde, Cameroon, Email: tambeelvis2008@yahoo.com, ORCID: https://orcid.org/0009-0007-5699-8999
Received: 11 Mar 2026, Accepted: 30 Aug 2026, Published: 01 Oct 2026
Domain: Infectious Disease Epidemiology
Keywords: Circulating vaccine-derived poliovirus; immunization inequality; health equity; Africa; DTP3
©Elvis Akem Tambe et al. Journal of Interventional Epidemiology and Public Health (ISSN: 2664-2824). This is an Open Access article distributed under the terms of the Creative Commons Attribution International 4.0 License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Cite this article: Elvis Akem Tambe et al., Wealth-related immunization inequality and circulating vaccine-derived poliovirus occurrence and burden in Africa from 2015 to 2024. Journal of Interventional Epidemiology and Public Health. 2026;9(ConfPro8):08. https://doi.org/10.37432/JIEPH-CONFPRO8-0008
Despite Africa’s certification as wild poliovirus-free in 2020, circulating vaccine-derived poliovirus (cVDPV) continues to threaten eradication progress. National immunization coverage averages may conceal socioeconomic pockets of under-immunized children. This study examined whether wealth-related inequality in immunization coverage was associated with cVDPV occurrence and burden across African countries and territories
A longitudinal ecological panel study was conducted across 58 African countries and territories from 2015 to 2024. The primary analytical sample included 402 country-years from 44 countries and territories with usable wealth-quintile immunization data and survey lag ≤7 years. The exposure was the survey-assigned third dose of diphtheria-tetanus-pertussis-containing vaccine (DTP3) wealth gap, defined as richest-quintile minus poorest-quintile coverage and scaled per 10 percentage-point increase. cVDPV occurrence was defined as any confirmed case in a country-year; burden was the annual confirmed case count. Generalized estimating equation logistic regression and negative binomial regression were used, adjusting for national third dose of polio-containing vaccine (Pol3) coverage, survey lag, conflict/fragility status, calendar year, and population structure as appropriate.
Ninety-nine of 402 country-years (24.6%) had at least one confirmed cVDPV case. Occurrence increased across DTP3 wealth-gap quartiles from 10.6% to 12.4%, 25.0%, and 50.5%. Each 10 percentage-point increase in the survey-assigned DTP3 wealth gap was associated with higher odds of cVDPV occurrence (odds ratio [OR] 1.47, 95% confidence interval [CI] 1.13–1.91) and higher cVDPV burden (incidence rate ratio [IRR] 1.38, 95% CI 1.11–1.71). Findings were broadly robust across sensitivity analyses.
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