Factors affecting hesitancy toward COVID-19 vaccine booster doses in Canada: a cross-national survey.

Objective: COVID-19 transmission, emergence of variants of concern, and weakened immunity have led to recommended vaccine booster doses for COVID-19. Vaccine hesitancy challenges broad immunization coverage. We deployed a cross-national survey to investigate knowledge, beliefs, and behaviours toward continued COVID-19 vaccination.

Methods: We administered a national, cross-sectional online survey among adults in Canada between March 16 and March 26, 2022. We utilized descriptive statistics to summarize our sample, and tested for demographic differences, perceptions of vaccine effectiveness, recommended doses, and trust in decisions, using the Rao-Scott correction for weighted chi-squared tests. Multivariable logistic regression was adjusted for relevant covariates to identify sociodemographic factors and beliefs associated with vaccine hesitancy.

Results: We collected 2202 completed questionnaires. Lower education status (high school: odds ratio (OR) 1.90, 95% confidence interval (CI) 1.29, 2.81) and having children (OR 1.89, CI 1.39, 2.57) were associated with increased odds of experiencing hesitancy toward a booster dose, while higher income ($100,000-$149,999: OR 0.60, CI 0.39, 0.91; $150,000 or more: OR 0.49, CI 0.29, 0.82) was associated with decreased odds. Disbelief in vaccine effectiveness (against infection: OR 3.69, CI 1.98, 6.90; serious illness: OR 3.15, CI 1.69, 5.86), disagreeing with government decision-making (somewhat disagree: OR 2.70, CI 1.38, 5.29; strongly disagree: OR 4.62, CI 2.20, 9.7), and beliefs in over-vaccinating (OR 2.07, CI 1.53, 2.80) were found associated with booster dose hesitancy.

Conclusion: COVID-19 vaccine hesitancy may develop or increase regarding subsequent vaccines. Our findings indicate factors to consider when targeting vaccine-hesitant populations.