Predictors of the willingness to accept a free COVID-19 vaccine among households in Nigeria

Background: To inform vaccination policy and programmatic strategies to increase COVID-19 vaccine uptake, an understanding of the factors associated with the willingness to vaccinate is needed. Methods: We analyzed data collected from the sixth and tenth round of the Nigerian COVID-19 National Longitudinal Phone Survey conducted by the National Bureau of Statistics and the World Bank in 2020 and 2021, respectively. Exploratory data analysis and feature selection techniques were used to identify important variables. Multivariable logistic regression models were fitted to assess the association between socio-demographic and economic factors and the willingness to receive a free COVID-19 vaccine among Nigerian households at two different time points before vaccines became widely available. Results: Data from 1,733 and 1,651 Nigerian households who completed the sixth and tenth round of the survey, respectively, were included. Most respondents (>85% of households) were willing to receive a free COVID-19 vaccine from both survey rounds. The median household size was 6 (IQR: [4, 8]) with females heading about 18% of the households. Approximately 22% of the household heads had not received any formal education. Compared to households whose head had no education, households whose heads had completed tertiary education or higher had significantly lower odds of willingness to be vaccinated (OR round 6 : 0.46, 95% CI: [0.31, 0.68], OR round 10 :0.49, 95% CI: [0.34, 0.71]). An increasing proportion of male household members was associated with greater willingness to receive a free COVID-19 vaccine (OR round 6 :1.84, 95% CI: [1.01, 3.33], OR round 10: : 5.25, 95% CI: [2.86, 9.65]). Significant associations with vaccine willingness were also observed across geopolitical zones of residence with households in South-East Nigeria (OR round 6 : 0.16, 95% CI: [0.10, 0.24]; OR round 10 :0.29, 95% CI: [0.19, 0.43]) and South-South Nigeria (OR round 6 :0.57, 95% CI: [0.36, 0.90], OR round 10: : 0.32, 95% CI: [0.22, 0.48]) less likely to be willing to receive a free vaccine compared to households in North-Central Nigeria. Conclusion: These findings from two different time points before vaccine roll-out suggest that the educational level of household head, proportion of male household members, and the geopolitical zone of residence are important baseline predictors of the willingness to receive a free COVID-19 vaccine in Nigeria. These factors should be carefully considered and specifically targeted when designing public health programs to inform early- stage strategies that address underlying vaccine hesitancy, improve vaccine uptake, promote ongoing COVID-19 vaccination efforts, and potentially enhance other immunization programs in Nigeria.