COVID-19 booster vaccine acceptance in North Central Nigeria: An application of the Integrated Behavioural Model

Introduction: The limited protection durability of the primary COVID-19 vaccines and the existential threats of variants with evasive mechanisms have necessitated the need to roll out booster vaccines in many countries. Against the backdrop of vaccine hesitancy in Nigeria, this study aimed to investigate acceptance of COVID-19 booster vaccine using an integration of behavioural models, namely the Health Belief Model (HBM)and the Theory of Planned Behaviour (TPB). Methods: The research was a cross-sectional sub-population study nested within a larger survey. The parent study was conducted to investigate the determinants of COVID-19 vaccine acceptance in Ilorin, North central Nigeria. The nested study employed a purposive sampling technique and included all 339 respondents who had completed the primary vaccine series. We performed univariate and bivariate analysis. We used hierarchical logistic regression to predict acceptance of a COVID-19 booster vaccine. Results: The prevalence of COVID-19 booster acceptance was high (83%). The integrated model could explain 42.3% of the variance in the acceptance of COVID-19 booster vaccine (aR2 = 0.423). Awareness of COVID-19 booster vaccine was predictive of its acceptance (OR: 5.03, CI: 2.21 – 11.43). Predicators of booster vaccine acceptance were perceived benefits (aOR: 0.75, CI: 0.64-0.88) according to the HBM; self-efficacy (aOR= 0.71, CI: 0.52-0.97) and of subjective norms (OR: 0.83, CI: 0.73-0.94) according to the TPB. Conclusion: This study demonstrated the significance of combining models in investigating acceptance of COVID-19 vaccine. To allow for informed booster vaccination acceptance, we recommend increased risk communication, effective public health education and information and the use of social influence marketing to promote the acceptance of the booster vaccine.