Infectious Disease
Assessing coverage of recommended vaccinations for older adults: An analysis of the Canadian Longitudinal Study on Aging Angelina Sassi* Angelina Sassi Nicole E. Basta Christina Wolfson
Preventing infectious diseases among older adults is crucial to healthy aging. The risk associated with influenza, pneumococcal pneumonia, herpes zoster (HZ), and COVID-19 can be significantly reduced via vaccination. Assessing vaccine uptake of these recommended vaccines is an important first step in identifying opportunities to improve prevention efforts among older adults. The Canadian Longitudinal Study on Aging (CLSA) provides a unique opportunity to estimate vaccination coverage for multiple vaccines among a large cohort of older adults where extensive data has been collected. Using CLSA data from 2018-2021, we aimed to go beyond national estimates reporting the uptake of each vaccine to determine the proportion of Canadian adults aged 65 years and older who are “fully vaccinated” (received influenza vaccine within the past 12 months and received pneumococcal and HZ vaccine in their lifetime, as recommended), “under vaccinated” (vaccinated with at least one of these vaccines but not all), and “non-vaccinated” (not vaccinated with any of these vaccines). We then aimed to evaluate the association between multiple socio-demographic and health care utilization factors and being under-vaccinated and non-vaccinated, compared to being fully vaccinated, using multivariable, multinomial logistic regression models. Of the 10,432 adults aged 65 and older eligible for our analysis, 51.4% were under-vaccinated due to missed influenza, pneumococcal, or HZ vaccination (95% CI: 50.5 – 52.4%). Specifically, 18.5% missed HZ vaccine only (95% CI: 17.8 – 19.3%), 13.2% missed both HZ and pneumococcal vaccines (95% CI: 12.6 – 13.9%), 9.7% missed pneumococcal vaccine only (95% CI: 9.2 – 10.3%), and 10% missed influenza vaccine (only or with one other vaccine) (95% CI: 9.4 – 10.5%). Additionally, 17.3% were non-vaccinated (95% CI: 16.6 – 18.1%). These results provide new insights into gaps in vaccine uptake among Canadian older adults and indicate key areas for future interventions.