A Missed Opportunity? Exploring Changes in Influenza Vaccination Coverage During the COVID-19 Pandemic: Data From 12 Countries Worldwide.

BACKGROUND

Vaccination is a key measure in influenza control, yet global coverage rates remain low, although previous research reported an increase in influenza vaccination coverage rates (VCR) after the onset of the COVID-19 pandemic. This study aims to assess whether these changes were sustained over time by analyzing VCR trends from 2012 to 2023 in the countries included in the FluCov project.

METHODS

Data on influenza VCR from 2012 to 2023 for different age and risk groups were extracted from national health organizations and international sources for countries included in the FluCov project. For coverage rates in the older adults, segmented regression models were used to test if 2020 marked a significant change in VCR trends. Moreover, polynomial regression models were fitted for each country with VCR in the period 2012 to 2020 to predict coverage rates for 2021 to 2023 and to compare these to the actual coverage rates for 2021 to 2023.

RESULTS

For the elderly, we retrieved influenza VCR data for 12 countries. In 2020, VCR among elderly increased in 10 countries, but the increase was statistically significant in Spain and England only. Moreover, all countries except Spain reverted to levels within the confidence intervals of trends modeled using pre-2020 data.

CONCLUSIONS

Although influenza VCR increased in 2020, these changes were statistically significant in only two out of 12 countries, and no consistent, sustained increase was observed afterward, except in Spain. The findings suggest the need for continuous monitoring of VCR and the implementation of strategies to promote and maintain high vaccination coverage rates.