Conference Abstract | Volume 9 (ConfPro8): Abstract 85 | Published: 11 Oct 2026
Mary Yetunde Ajayi1,&, Adeola Akintola2
1Sydani Initiative for International Development, Abuja, Nigeria, 2Center for Bioethics and Research, Ibadan, Nigeria
&Corresponding author: Mary Yetunde Ajayi, Sydani Initiative for International Development, Abuja, Nigeira, Email: kodaolumary@gmail.com, ORCID: https://orcid.org/0000-0001-6989-8777
Received: 11 Mar 2026, Accepted: 30 Aug 2026, Published: 11 Oct 2026
Domain: Infectious Disease Epidemiology
Keywords: Childhood immunization, vaccine uptake, BCG, measles, pentavalent
©Mary Yetunde Ajayi 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: Mary Yetunde Ajayi et al., Geographic inequalities in vaccine completion and dropout along the childhood immunization continuum in Nigeria: Analysis of routine health information system data, 2021–2025. Journal of Interventional Epidemiology and Public Health. 2026;9(ConfPro8):85. https://doi.org/10.37432/JIEPH-CONFPRO8-0085
Nigeria continues to bear a disproportionate burden of vaccine-preventable diseases, many of which are preventable through timely childhood immunization. Despite increasing investments to expand access, many children fail to complete the recommended vaccination schedule, resulting in preventable morbidity and mortality. This study assessed trends in vaccine uptake and completion along the childhood immunization continuum in Nigeria from 2021 to 2025 using routine DHIS2 data.
A retrospective descriptive analysis of routine family planning service-delivery data extracted from DHIS2 was conducted. Data on self-injected and provider-administered injectable contraceptive uptake from March to August 2026 were analyzed. Data were disaggregated by state, LGA, ward, and facility. Descriptive statistics, including frequencies, proportions, and percentage changes, were performed using Stata 17.
Uptake increased across all antigens between 2021 and 2025. BCG doses administered increased from 6.6 million to 8.4 million, Penta1 from 6.8 million to 9.0 million, Penta3 from 6.4 million to 8.6 million, MCV1 from 5.9 million to 8.1 million, and MCV2 from 2.4 million to 5.4 million doses. Pentavalent completion remained consistently high (92.8–95.3%) throughout the study period, while measles completion improved from 40.2% in 2021 to 65.7% in 2025. However, marked geographic disparities persisted. In 2025, measles completion ranged from 39.9% in Anambra State to 93.1% in Bauchi State, a 53.2 percentage-point difference. Completion was highest in the North-East (78.1%) and North-West (77.1%) and lowest in the South-East (49.3%) and South-South (57.8%).
Although vaccine uptake and pentavalent completion improved nationally, completion of the measles vaccine series remains suboptimal and inequitable. Targeted, equity-focused interventions are needed to strengthen retention along the immunization continuum and accelerate progress toward universal immunization coverage in Nigeria.
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