Determinants of SARS-CoV-2 Vaccine Willingness Among People Incarcerated in 3 Canadian Federal Prisons: a Cross-sectional Study

Background: Maximizing uptake of SARS-CoV-2 vaccines among people in prison is essential in mitigating future outbreaks. We aimed to determine factors associated with willingness to receive SARS-CoV-2 vaccination before vaccine availability.

Methods: We chose 3 Canadian federal prisons based on their low uptake of influenza vaccines in 2019-2020. Participants completed a self-administered questionnaire on knowledge, attitude and beliefs toward vaccines. The primary outcome was participant willingness to receive a SARS-CoV-2 vaccine, measured using a 5-point Likert scale to the question, "If a safe and effective COVID-19 vaccine becomes available in prison, how likely are you to get vaccinated?" We calculated the association of independent variables (age, ethnicity, chronic health conditions, 2019-2020 influenza vaccine uptake and prison security level), identified a priori, with vaccine willingness using logistic regression and crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs).

Results: We recruited 240 participants from Mar. 31 to Apr. 19, 2021 (median age 46 years; 19.2% female, 25.8% Indigenous). Of these, 178 (74.2%) were very willing to receive a SARS-CoV-2 vaccine. Participants who received the 2019-2020 influenza vaccine (adjusted OR 5.20, 95% CI 2.43-12.00) had higher odds of vaccine willingness than those who did not; those who self-identified as Indigenous (adjusted OR 0.27, 95% CI 0.11-0.60) and in medium- or maximum-security prisons (adjusted OR 0.36, 95% CI 0.12-0.92) had lower odds of vaccine willingness than those who identified as white or those in minimum-security prisons, respectively.

Interpretation: Most participants were very willing to receive vaccination against SARS-CoV-2 before vaccine roll-out. Vaccine promotion campaigns should target groups with low vaccine willingness (i.e., those who have declined influenza vaccine, identify as Indigenous or reside in high-security prisons).