Exploring determinants of COVID-19 vaccine uptake in Tanzania: A socio-ecological perspective.

Background: The COVID-19 pandemic continues to challenge global public health, with vaccination playing a key role in mitigating transmission. Despite recognising its importance, Tanzania exhibits considerable regional disparities in vaccine uptake. Understanding the determinants influencing vaccination is essential.

Aim: This study investigated determinants of COVID-19 vaccination rates within Tanzania, employing a socio-ecological framework to comprehensively examine individual, interpersonal, community, and institutional influences.

Setting: Eight regions across Tanzania, purposively selected to represent urban, peri-urban, and rural contexts, reflecting varying socio-cultural and infrastructural conditions.

Methods: A concurrent mixed-method design was utilised, combining quantitative surveys from 3098 participants with qualitative data collected through focus group discussions and key informant interviews.

Results: Although general awareness of COVID-19 was notably high (99.3%), overall vaccine acceptance remained low (37.2%), exhibiting significant regional variations (22.5% in Morogoro to 50.0% in Mtwara). Individual factors such as personal vaccine beliefs, perceived safety, and misinformation significantly impacted uptake. Interpersonal influences from family, friends, and community leaders critically shaped vaccination decisions. Despite high acknowledgment of community leaders' roles (88.3%), governmental campaign awareness was minimal (22.4%). Institutional factors, notably healthcare system trust and vaccine accessibility, also significantly influenced uptake.

Conclusion: Findings advocate for region-specific, multilevel interventions addressing misinformation, engaging trusted community influencers, improving transparency, and enhancing healthcare service delivery to mitigate disparities and enhance vaccine acceptance.

Contribution: The study offers insights foundational for tailored public health strategies, improving vaccine accessibility and resilience against future pandemics in Tanzania and comparable socio-ecological contexts.