COVID-19 vaccine uptake in immigrant, refugee, and nonimmigrant children and adolescents in Ontario, Canada

Importance — COVID-19 vaccinations are recommended for minors. Surveys indicate lower vaccine acceptance by some immigrant/refugee groups.

Objective — To identify characteristics in immigrant/refugee and non-immigrant minors associated with vaccination, across two distinct campaigns: for adolescents (12-18 years) starting May 23rd, 2021, and for children (5-11 years) starting November 25th, 2021, through April 24, 2022.

Design — A retrospective cohort study using linked, population-based, demographic and healthcare data.

Setting — Ontario/Canada.

Participants — All children aged 4-17 registered for universal health insurance on January 1st, 2021.

Exposures — Immigrant/refugee status and immigration characteristics (recency, category, region of origin and generation).

Main Outcome(s) and Measure(s) — Crude rates of COVID-19 vaccination (children ≥1 vaccination; adolescents ≥2 vaccinations) and odds ratios with 95% confidence intervals (CI) adjusted for clinical, sociodemographic and health system factors.

Results — Among the 2.2 million study cohort, 4.8% (53,090/1,098,749) of children and 9.2 (104,975/1,142,429) of adolescents were first generation, and 23.4% (256,886/1,098,749) and 19.4%(221,981/1,142,429) second generation immigrants/refugees, the majority being economic/family class immigrants. Immigrants, particularly refugees, were more likely to live in neighbourhoods with highest material deprivation (first generation children/adolescents: immigrants 18.6%/20.2%, refugees 46.4%/46.3%, non-immigrants 18.5%/17.2%) and COVID-19 risk (first generation children/adolescents: immigrants 20.0%/20.5%, refugees 9.4%/12.6%, non-immigrants 6.9%/6.8%). Vaccination rates (53.1% in children and 79.2% in adolescents) were negatively associated with material deprivation. In both age groups, adjusted odds [aOR] for vaccination were higher in immigrants (children: aOR=1.30, CI: 1.27-1.33; adolescents: aOR=1.10, CI: 1.08-1.12) but lower in refugees (children: aOR=0.34, CI: 0.33-0.36; adolescents: aOR=0.88, CI: 0.84-0.91) compared to non-immigrants. In immigrant/refugee-only models stratified by generation, region of origin was associated with uptake (compared to the overall average) (lowest: Eastern Europe (children aOR=0.40, CI: 0.35-0.46; adolescents aOR=0.41, CI: 0.38-0.43) and Central Africa (children aOR=0.24, CI: 0.16-0.35; adolescents aOR=0.51,CI: 0.45-0.59); highest: Southeast Asia (children aOR=2.68, CI: 2.47-2.92; adolescents aOR=4.42, CI: 4.1-4.77)). Adjusted ORs of regions with lowest vaccine coverage were similar across generations.

Conclusions — In this Canadian study, non-refugee immigrants had higher vaccine coverage than non- immigrants. Substantial heterogeneity by region of origin and lower vaccination coverage in refugees persisted across generations. Vaccine campaigns need precision public health approaches targeting specific barriers in identified, undervaccinated subgroups.