OBJECTIVES: The circulation of the SARS-Cov2 responsible of the COVID-19 pandemic was still active during the 2021/22 influenza season. As such, immunization against influenza was still highly recommended to protect populations and relief healthcare systems. The objective of this study was to observe the evolution of influenza vaccines sales during the pooled 2020/22 seasons compared to pre-COVID-19 influenza seasons.

METHODS: Leveraging previous research, we focused on influenza vaccine sales or prescription/reimbursement for the influenza seasons 2015/16 to 2021/22 in three countries: France, UK and US. Data were collected for each season from September/October to January/February. Data for France were extracted from the Assurance Maladie (reimbursement data) while data for the UK were selected from the Vantage IQ database (prescription data), and data from the CDC were considered for the US (distributed doses). We used non-parametric Wilcoxon signed-rank tests to highlight significant vaccine sales variations for the combined 2020/22 seasons compared to previous seasons.

RESULTS: A +26.28% increase in reimbursed influenza vaccines was observed in France for the combined 2020/22 seasons compared to the pre-COVID-19 period (p=0.0313), with significant augmentations observed for each month from October to February. Similar observations were noted for the UK and the US, with overall increases of +28.83% (prescribed vaccines) and +16.21% (distributed vaccines) respectively (p= 0.0313). However, reductions in vaccine volumes were noted between the 2020/21 and 2021/22 seasons in France and the US, with -12.26% and -11.00% respectively.

CONCLUSIONS: We observed a significant increase in influenza vaccine sales for the seasons 2020/22 compared to pre-COVID-19 seasons, most likely attributable to the Covid-19 pandemic. However, drops in influenza vaccine volumes were observed in 2021/22 for France and the US compared to 2020/21, highlighting potential early signs of vaccine fatigue and drop in awareness, with the risk of returning to pre-COVID-19 vaccine volume levels.