Knowledge, attitudes, perceptions and reported uptake of COVID-19 vaccines among adults in Tanzania: a mid-pandemic population-based cross-sectional survey

SARS-CoV-2 and the COVID-19 vaccines became subjects of conspiratorial thinking and widespread misinformation, which fueled vaccine hesitancy worldwide. This study investigated the levels of knowledge, attitudes, and perceptions regarding the COVID-19 vaccine and its uptake. Additionally, we assessed factors associated with the reported uptake of the COVID-19 vaccine among individuals aged 18 years and above in four regions of Tanzania. An interview form with structured questions was used to collect data on sociodemographic characteristics, reported COVID-19 vaccine uptake, knowledge, attitudes, and perceptions from adults aged 18 years and above across the four study sites, between August and September 2022. Multivariable binary logistic regression analysis was employed to identify factors associated with the uptake of the COVID-19 vaccine. A two-tailed p-value of < 0.05 was considered statistically significant. A total of 22,910 study participants were interviewed, and 19.1% reported having received the COVID-19 vaccine. Factors significantly associated with reported vaccine uptake included having good knowledge about the vaccine (aOR = 2.4, 95% CI: 2.21–2.69), a positive attitude towards the vaccine (aOR = 9.1, 95% CI: 8.00–10.38), presence of a chronic disease (aOR = 2.0, 95% CI: 1.81–2.27), being aged 50 years or older (aOR = 8.8, 95% CI: 6.21–12.47), and living with a partner (aOR = 1.2, 95% CI: 1.12–1.25). By the mid of the pandemic and nearly a year after the COVID-19 vaccine rollout in Tanzania, fewer than one in five adults had been vaccinated. This low uptake was unexpected given the generally good knowledge, attitudes, and perceptions observed. Uptake was influenced by multiple sociodemographic and clinical factors in a context-specific manner. These findings highlight the importance of continued, tailored health education to address emerging infectious diseases like COVID-19 and promote acceptance of related public health interventions.