The impact of the COVID-19 pandemic on routine immunizations in Canada

Abstract

Study 1: Introduction In Canada, the COVID-19 pandemic has interrupted many routine health services, placed additional strain on the health care system, and resulted in many Canadians being either unable or unwilling to attend routine immunization appointments. We sought to capture and synthesize information about changes to routine immunization programs in response to the pandemic and plans to catch-up any missed immunizations. Methods Provincial/territorial (P/T) public health leaders were interviewed via teleconference between August-October 2020 to collect information on the following topics: how routine immunization delivery was affected during and after initial lockdown periods, plans to catch-up missed doses, and major challenges and achievements in continuing routine immunization programs. Data were coded and categorized according to common responses and descriptive analysis was performed. Results Interviews occurred with participants from 11 of 13 P/Ts. School immunization programs were reported to be most negatively affected by the pandemic (n=9). In the early pandemic period, infant, preschool, and maternal/prenatal programs were prioritized, with most P/Ts continuing these services with adaptations for COVID-19. After the initial lockdown period, all routine programs were continuing with adaptations in most P/Ts. Infant, preschool, and school programs were most often targeted for catch-up through measures such as appointment rebooking and making additional clinics and/or providers available. Major challenges included resource limitations (e.g., staff shortages, PPE shortages, limited infrastructure) (n=11), public health restrictions (n=8), and public hesitancy to attend appointments (n=5). Conclusions Canadian routine immunization programs faced some disruptions due to the COVID-19 pandemic, particularly the school, adult, and older adult programs. Further research is needed to determine the measurable impact of the pandemic on routine vaccine coverage levels. Study 2: Introduction Routine immunization programs have been disrupted by the coronavirus disease 2019 (COVID-19) pandemic globally, but little is known about the impact on school immunization coverage in Canada. The objectives of this study were to: 1) assess the change in coverage for two school-based vaccines in Alberta, Canada, before and during the pandemic; 2) ascertain whether coverage has returned to pre-pandemic levels; and 3) determine whether coverage differed by school zone and type. Methods Using a retrospective cohort study of administrative health data in Alberta, this study compared absolute differences in coverage for human papillomavirus (HPV) and meningococcal conjugate A, C, Y, W-135 (MenC-ACYW) vaccines between pre-pandemic (2017-2018 school year) and pandemic (2019-2020 and 2020-2021 school years) cohorts using Pearson’s chi-square tests. Coverage was also compared by school zone (Calgary, Edmonton, Central, North, South) and authority type (public, Catholic, private, charter, francophone) by calculating crude relative risks. The 2019-2020 cohort was followed over a one-year period to assess catch-up. Results Compared to the 2017-2018 cohort, at the end of the school year, immunization coverage for HPV was significantly lower in the 2019-2020 (absolute difference: 60.8%; 95% CI: 60.4-61.3%) and 2020-2021 cohorts (absolute difference: 59.9%; 95% CI: 59.4-60.3%). There was a smaller, significant decline in MenC-ACYW coverage comparing 2017-2018 to 2019-2020 (absolute difference: 6.1%; 95% CI: 5.6-6.5%) and 2020-2021 (absolute difference: 32.2%; 95% CI: 31.6-32.7%). Private schools had low coverage for both vaccines in both cohorts, while coverage fluctuated by zone. During follow-up, coverage for HPV and MenC-ACYW improved in the 2019-2020 cohort, increasing from 5.6% to 50.2%, and 80.7% to 83.0%, respectively. Conclusion HPV and MenC-ACYW coverage during the COVID-19 pandemic declined in comparison to pre-pandemic, and coverage also differed by school zone and type. Coverage has not yet returned to pre-pandemic levels, suggesting further catch-up is needed.