BJAR British Journal of Advanced Research BJAR 3153-709X Ivory and Finch Publishers 10.68263/BJAR-HPGG87NJ BJAR_AUG_26_039 Original Research Article Determinants of Second-Dose Measles Vaccination Uptake Among Children Aged 15-23 Months in Benin City, Nigeria: A Mixed-Methods Study Daniel Onowugbeda Efemena https://orcid.org/0000-0003-0405-9379 Department of Public Health and Community Medicine, Benson Idahosa University and Department of Public Health and Community Medicine, University of Benin Teaching Hospital tufdan@gmail.com Agbalugo Odunze Pius Department of Community Medicine, Gombe State University Trinitas Omonigho Oghenerukevwe Edo State Health Insurance Commission Joshua Orifunmishe Oreoluwa Department of Public Health and Community Medicine, University of Benin Teaching Hospital Yakubu Adam Vincent Department of Public Health and Community Medicine, University of Benin and Department of Public Health and Community Medicine, University of Benin Teaching Hospital Ngozi Ofili Antoinette Department of Public Health and Community Medicine, University of Benin and Department of Public Health and Community Medicine, University of Benin Teaching Hospital 10 09 2026 1 3

Background: Nigeria introduced a second dose of measles-containing vaccine (MCV2) to improve population immunity, but second-year uptake remains insufficiently described in urban settings. Objective: To determine MCV2 uptake, MCV1-MCV2 dropout, associated factors, and caregiver-reported barriers among age-eligible children in Benin City. Methods: This mixed-methods cross-sectional study analysed 460 children aged 15-23 months from a survey of 620 caregiver-child pairs. Six focus group discussions involved 54 mothers. Pearson's chi-square test and multivariable logistic regression assessed factors associated with MCV2 receipt; qualitative data were analysed thematically. Results: MCV1 and MCV2 uptake were 90.0% and 82.2%, respectively. Among MCV1 recipients, dropout was 9.7%. Antenatal-care attendance and health-facility delivery were associated with uptake at bivariate analysis. After adjustment, antenatal-care attendance remained independently associated with MCV2 receipt (adjusted odds ratio 3.71; 95% confidence interval 1.72-8.01). Caregivers described poor awareness, forgetfulness, weak reminders, competing responsibilities, occasional service unavailability, and distance. Conclusion: MCV2 uptake remained below the 95% elimination target. Antenatal and immunisation counselling, reliable sessions, reminder-recall systems, and active defaulter tracking should be strengthened.

 Antenatal Care Measles Mixed Methods Second Year of Life Vaccine Dropout Vaccine Uptake 29 08 2026 31 08 2026 Copyright © 2026 by the authors This article is distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. References Adamu, A. A., Uthman, O. A., Gadanya, M. A., & Wiysonge, C. S. (2024). Mapping the implementation determinants of second dose of measles-containing vaccine: A scoping review. Vaccines, 12(8), 921. https://doi.org/10.3390/vaccines12080921 Adugna, B., Tola, A., Fite, M. B., & Motuma, A. (2024). Determinants of second-dose measles vaccination dropout in Ethiopia: A community-based matched case-control study. Heliyon, 10, e30764. https://doi.org/10.1016/j.heliyon.2024.e30764 Alemu, T. G., Tamir, T. T., Workneh, B. S., Mekonen, E. G., Ali, M. S., Zegeye, A. F., et al. (2024). Coverage and determinants of second-dose measles vaccination among under-five children in East Africa countries: A systematic review and meta-analysis. Frontiers in Public Health, 12, 1359572. https://doi.org/10.3389/fpubh.2024.1359572 Baptiste, A. E. J., Wagai, J., Hahne, S., Adeniran, A., Koko, R. I., de Vos, S., Shibeshi, M., Sanders, E. A. M., Masresha, B., & Hak, E. (2024). High-resolution geospatial mapping of zero-dose and underimmunized children following Nigeria's 2021 Multiple Indicator Cluster Survey/National Immunization Coverage Survey. Journal of Infectious Diseases, 230(1), e131-e138. https://doi.org/10.1093/infdis/jiad476 Bolarinwa, O. A. (2020). Sample size estimation for health and social science researchers: The principles and considerations for different study designs. Nigerian Postgraduate Medical Journal, 27(2), 67-75. https://doi.org/10.4103/npmj.npmj_19_20 Eze, P., Agu, U. J., Aniebo, C. L., Agu, S. A., Lawani, L. O., & Acharya, Y. (2021). Factors associated with incomplete immunisation in children aged 12-23 months at subnational level, Nigeria: A cross-sectional study. BMJ Open, 11(6), e047445. https://doi.org/10.1136/bmjopen-2020-047445 Fenta, S. M., Biresaw, H. B., Fentaw, K. D., & Gebremichael, S. G. (2021). Determinants of full childhood immunization among children aged 12-23 months in sub-Saharan Africa: A multilevel analysis using Demographic and Health Survey data. Tropical Medicine and Health, 49, 29. https://doi.org/10.1186/s41182-021-00319-x Gebeyehu, N. A., Gelaw, K. A., Lake, E. A., Adela, G. A., Tegegne, K. D., & Shewangashaw, N. E. (2022). Vaccination dropout among children in sub-Saharan Africa: Systematic review and meta-analysis. Human Vaccines & Immunotherapeutics, 18(7), 2145821. https://doi.org/10.1080/21645515.2022.2145821 Ibraheem, R., Akintola, M., Abdulkadir, M., Ameen, H., Bolarinwa, O., & Adeboye, M. (2021). Effects of call reminders, short message services reminders, and SMS immunization facts on childhood routine vaccination timing and completion in Ilorin, Nigeria. African Health Sciences, 21(2), 951-959. https://doi.org/10.4314/ahs.v21i2.57 Ibrahim, H. A., Wariyo, A., Asefa, E. M., Cheru, A., Abebe Lonsako, A., & Dirirsa, G. (2024). Measles second dose vaccine uptake and associated factors among under-five children in Jigjiga City, Somali Region, Eastern Ethiopia: A community-based cross-sectional study. Frontiers in Public Health, 12, 1395802. https://doi.org/10.3389/fpubh.2024.1395802 Masresha, B. G., Dixon, M. G., Kriss, J. L., et al. (2024). Progress with the second dose measles vaccine introduction and coverage in the WHO African Region. Vaccines, 12(9), 1069. https://doi.org/10.3390/vaccines12091069 Melis, T., Hassen, H. Y., Lera, T., et al. (2023). Predictors for low coverage of uptake of second dose of measles vaccine among children in sub-Saharan Africa: A multilevel analysis. PLOS ONE, 18, e0294766. https://doi.org/10.1371/journal.pone.0294766 Mulatu, A., Tsega, Y., Cherie, N., Kasaye, M. D., & Mekonen, A. M. (2025). Uptake of second dose measles containing vaccine and associated factors among children aged 24-35 months in central Ethiopia: A community-based cross-sectional study. BMC Public Health, 25, 1470. https://doi.org/10.1186/s12889-025-22750-z Obi-Jeff, C., Garcia, C., Adewumi, F., Bamiduro, T., David, W., Labrique, A., & Wonodi, C. (2022). Implementing SMS reminders for routine immunization in Northern Nigeria: A qualitative evaluation using the RE-AIM framework. BMC Public Health, 22, 2370. https://doi.org/10.1186/s12889-022-14822-1 Sato, R. (2024a). How did the introduction of the measles-containing vaccine second dose (MCV2) affect measles vaccine uptake? Evidence from Nigeria. Human Vaccines & Immunotherapeutics, 20(1), 2355036. https://doi.org/10.1080/21645515.2024.2355036 Sato, R. (2024b). Trends of the second measles vaccine (MCV2) over time after its launch as part of routine immunization in Nigeria: A brief research report. Frontiers in Public Health, 12, 1392996. https://doi.org/10.3389/fpubh.2024.1392996 Tadesse, A. W., Sahlu, D., & Benayew, M. (2022). Second-dose measles vaccination and associated factors among under-five children in urban areas of North Shoa Zone, Central Ethiopia, 2022. Frontiers in Public Health, 10, 1029740. https://doi.org/10.3389/fpubh.2022.1029740 Taffie, W., Temesgen, H., Ashebir, W., & Mekonen, H. (2024). Measles second dose vaccine uptake and its associated factors among children aged 24-35 months in Northwest Ethiopia, 2022. Scientific Reports, 14, 11059. https://doi.org/10.1038/s41598-024-61048-9 Williams, S. V., Akande, T., & Abbas, K. (2024). Systematic review of social determinants of childhood immunisation in low- and middle-income countries and equity impact analysis of childhood vaccination coverage in Nigeria. PLOS ONE, 19(3), e0297326. https://doi.org/10.1371/journal.pone.0297326 World Health Organization. (2017). Measles vaccines: WHO position paper - April 2017. Weekly Epidemiological Record, 92(17), 205-228. World Health Organization. (2018). World Health Organization vaccination coverage cluster surveys: Reference manual. https://iris.who.int/handle/10665/272820 World Health Organization. (2024). Measles. https://www.who.int/news-room/fact-sheets/detail/measles