Abstract:
Introduction: Measles remains a major public health challenge in Nigeria despite the availability of a safe and effective vaccine. Recurrent outbreaks in Edo State between 2020 and 2025 suggested persistent immunity gaps and raised concerns regarding the effectiveness of the routine measles immunization programme. This evaluation assessed programme performance, vaccination coverage trends, surveillance outcomes, and operational barriers affecting measles control in Edo State.
Methods: A mixed-methods programme evaluation was conducted using routine immunization data, measles surveillance data, and field-based assessments. Statewide vaccination coverage and surveillance data from 2021–2025 were analyzed to assess trends in measles-containing vaccine first dose (MCV1), second dose (MCV2), dropout rates, and reported measles cases. Primary data were collected through a structured Kobobased assessment involving 142 participants across six purposively selected Local Government Areas (LGAs). The evaluation was guided by the CDC Framework for Program Evaluation in Public Health and WHO immunization programme assessment guidance.
Results: Mean MCV1 coverage increased from 39.7% in 2021 to 54.5% in 2025, while MCV2 coverage increased from 20.3% to 35.2%. Despite these improvements, both indicators remained substantially below the 95% coverage threshold required for measles elimination. Dropout between MCV1 and MCV2 declined from 49.4% to 35.9% but remained high. Significant geographic inequities were observed, with 2025 MCV1 coverage ranging from 16.1% to 86.4% and MCV2 coverage ranging from 9.5% to 64.6% across LGAs. A total of 931 measles cases were reported between 2020 and 2025, with cases increasing from 146 in 2023 to 228 in 2024, indicating continued transmission despite improving vaccination coverage. Field assessments found that microplanning, supervision, and routine data systems were largely in place; however, weaknesses persisted in cold chain functionality, staffing adequacy, outreach implementation, and use of data for corrective action. Misinformation, distance to health facilities, and security concerns were the most commonly reported barriers to vaccination uptake.
Conclusions: Although measles vaccination coverage has improved in Edo State, persistent dropout, geographic inequities, operational challenges, and community-level barriers continue to sustain immunity gaps and ongoing measles transmission. Strengthening defaulter tracking, prioritizing low-performing LGAs, improving cold chain performance, and expanding community engagement are critical to accelerating progress toward measles elimination.
Biography:
Musonda Chikwanda is an African Epidemiology Service (AES) Fellow at Africa Centres for Disease Control and Prevention with experience in infectious disease surveillance, outbreak investigation, programme evaluation, and public health emergency response. She has supported investigations and evaluations involving measles, cholera, diphtheria, meningitis, and other priority diseases in Nigeria. Her interests include epidemiology, surveillance systems strengthening, immunization programmes, and health security in Africa.
