Key Points

COVID-19

• The period from July 2021 to June 2022 was marked by three waves of the COVID-19 epidemic and the onset of a fourth wave, corresponding to waves 4 through 7 of the COVID-19 pandemic. These waves resulted in more than 3 million confirmed cases of SARS-CoV-2 infection and nearly 40,000 hospitalizations for COVID-19, including more than 5,000 in critical care in Auvergne-Rhône-Alpes during this period.

Influenza

• The 2021–2022 winter influenza epidemic in Auvergne-Rhône-Alpes lasted 17 weeks; it began in week 52 of 2021, peaked in week 12 of 2022 (March 21–27, 2022), and ended in week 16 of 2022. The pre-epidemic period began in week 50 of 2021, and the post-epidemic period ended in week 18 of 2022 in the region. Co-circulation of the influenza A(H1N1)pdm09 and A(H3N2) viruses was observed.

• The 2021–2022 epidemic was of moderate intensity—comparable to 2019–2020—in community practice and hospitals, and occurred later than usual, with the epidemic peak shifting to the spring, linked to reduced adherence to preventive measures following the fifth wave of COVID-19. Indicators in community practice and hospitals suggest that the impact of this epidemic was more pronounced among children under 15 years of age. This may be due to the absence of a flu epidemic in 2020–2021, resulting in lower exposure of young children to influenza viruses; this occurred even as flu vaccination coverage among older adults had increased compared to the pre-pandemic period.

Bronchiolitis

• The 2021–2022 bronchiolitis epidemic in Auvergne-Rhône-Alpes began in week 41 of 2021, peaked in week 48 of 2021 (November 29–December 5, 2021), and ended in week 1 of 2022. It lasted 13 weeks, slightly longer than is usually observed, with an intensity comparable to that of 2019–2020 at the peak of the outbreak but occurring slightly earlier, by about 2 weeks.