Influenza and COVID-19 vaccination in Canadian blood donors: A comparison across pre- and post-pandemic periods.

BACKGROUND AND

OBJECTIVES

Seasonal vaccinations reduce donor illness and appointment cancellations and ensure plasma products have antibodies to vaccine-directed strains. We aimed to describe donor influenza and COVID-19 vaccination history and compare this with the general population.

MATERIALS AND

METHODS

Two online donor surveys were carried out in 2021 and 2024. Donors were asked about demographics, influenza (2019/2020, 2020/2021 and 2023/2024 seasons) and COVID-19 (ever and 2023/2024 season) vaccination and reasons for vaccination choices. General population vaccination statistics were extracted from public reports. Percentages of donors receiving vaccination were calculated with 95% confidence intervals. Multiple logistic regression models were fitted with demographics as independent variables.

RESULTS

In survey 1, 4582 (30.4% response rate) donors completed a questionnaire; in survey 2, 6376 (21% response rate). More donors under age 65 received the influenza vaccine compared with the general population under age 65 (58% vs. 30% in 2019/2020, 63% vs. 28% in 2023/2024, p < 0.0001) and aged 65+ (81% vs. 70% in 2019/2020, 90% vs. 73% in 2023/2024, p < 0.0001). Fewer donors and the general population received the COVID-19 vaccine in 2023/2024 (under 65 45% vs. 39%; 65+ 76% vs. 67%, p < 0.0001). Most said they were vaccinated to prevent infection and protect others.

CONCLUSION

Seasonal vaccination rates are higher in older donors, consistent with public health recommendations. Blood donors are more likely to be vaccinated against seasonal influenza than the general population, but post-pandemic uptake of the COVID-19 booster vaccine was low, more similar to the general population.