Key Points

• The 2020–21 bronchiolitis epidemic in mainland France began in week 5 of 2021, peaked in week 13 of 2021, and ended in week 23 of 2021.

• It lasted 15 weeks, comparable to the previous season, though with a delay, peaking 13 weeks later than in the previous season.

• Its intensity was significantly lower than that of the previous season.

• The proportion of hospitalizations for bronchiolitis was comparable to recent seasons.

• In the French West Indies, epidemic thresholds were never exceeded.

• In Réunion and Mayotte, the epidemic that began in week 17 continues into week 24. In Mayotte, the epidemic continues to spread, suggesting that the peak may occur in the coming weeks. In Réunion, the epidemic is on the decline.