Understanding how influenza vaccine uptake changed during the 2020/2021 influenza season compared to past pre-pandemic seasons, as well as determining the link between prior influenza vaccination and willingness to get the COVID-19 vaccine, is a top objective. We studied data from a large, nationally representative cohort of Canadian citizens aged 50 and older three times between 2015 and 2020 to determine influenza vaccination status. Using logistic regression models, we looked at changes in selfreported influenza vaccine uptake, predictors of influenza vaccine uptake in 2020/2021, and the relationship between influenza vaccination history and self-reported COVID-19 vaccine willingness. Influenza vaccination rose with time among the 23,385 individuals assessed for goals 1–2: 14,114 (60.4 percent) in 2015–2018, 15,692 (67.1 percent) in 2019/2020, and 19,186 (82.0 percent) in 2020/2021 (combining those previously vaccinated and those expecting to acquire a vaccine). After accounting for multiple health and pandemic-related factors, history of influenza vaccination was most strongly associated with influenza vaccination in 2020/2021 (aOR 147.9 (95 percent CI: 120.9–180.9)). This association remained after accounting for multiple health and pandemic-related factors (aOR 140.3 (95 percent CI: 114.5–171.8)). Those who were most concerned about COVID-19 were also more likely to report influenza vaccination in autumn 2020, whereas those who said the pandemic had had a particularly negative impact were less likely to be vaccinated. Prior influenza vaccination was most strongly associated with willingness to get a COVID-19 vaccine (aOR 15.1 (95 percent CI: 13.5–16.8) for those who had received influenza vaccine at all previous time points versus none) among 23,819 participants with information on COVID-19 vaccine willingness during the last quarter of 2020 (aim 3). The impact of prior immunization in promoting vaccine uptake and willingness is shown in this study. Efforts to boost influenza and COVID-19 vaccine coverage should focus on those who don’t get immunizations on a regular basis, regardless of their demographics.
