Understanding factors influencing the implementation and uptake of less-established adult vaccination programmes: A meta-ethnography of COVID-19 vaccination in Nigeria.

Before COVID-19, a few studies examined adult vaccination programmes for disease outbreaks in Nigeria. Recent studies explored vaccine uptake factors, but few examined implementation. We aimed to understand factors influencing the implementation and uptake of adult vaccination programmes in Nigeria, through the COVID-19 example, to support subsequent outbreak interventions. We systematically searched seven databases and conducted a meta-ethnography of eight studies published between 2022 and 2024, involving 207 participants. Through reciprocal and refutational translation, higher-order interpretations, a new line of argument and a conceptual model on factors influencing implementation and uptake of COVID-19 vaccination in Nigeria were developed. We reported findings using eMERGe guidance. We developed eight higher-order interpretations operating at individual, health system and policy levels. Four concerned vaccination uptake: an ethical paradox, self-preservation, socioeconomic characteristics and trust. Another four concerned vaccination implementation and uptake: policy actions, local leadership from government, supply chain challenges and health services information. Our findings suggest that improved vaccination programme implementation during disease outbreaks in Nigeria would support enhanced vaccine uptake by adults. Our findings can inform vaccine implementation strategies for successful rollout and uptake of adult vaccines in future outbreaks.