SARS-CoV-2 testing, test positivity and vaccination in social housing residents compared with the general population: a retrospective population-based cohort study

Background — The consideration of unique social housing needs has largely been absent from the COVID-19 response, particularly in tailoring strategies to improve access to testing and vaccine uptake among vulnerable and high-risk populations in Ontario. Given the growing population of social housing residents, this study aimed to compare SARS-CoV-2 testing, positivity, and vaccination rates in a social housing population with those in a general population cohort in Ontario, Canada.

Methods — This population-based cohort study used administrative health data from Ontario to examine SARS-CoV-2 testing, positivity and vaccination rates in social housing residents compared with the general population from 1 January 2020 to 31 December 2021. All comparisons were unadjusted, stratified by sex and age and evaluated using standardised differences.

Results — The rates of SARS-CoV-2 PCR testing were lower among younger age groups and higher among older adults within the social housing cohort, compared with the general population cohort. SARS-CoV-2 test positivity was higher in social housing than in the general population among individuals aged 60–79 years (7.9% vs 5.3%, respectively) and 80 years and older (12.0% vs 7.9%, respectively). Overall, 34.3% of social housing residents were fully vaccinated, compared with 29.6% of the general population cohort. However, a smaller proportion of social housing residents had received a booster vaccine (36.7%) compared with the general population (52.4%).

Conclusion — Improved and targeted outreach strategies are needed to increase the uptake of COVID-19 booster vaccines among social housing residents.