Influenza A (H1N1)pdm09 and influenza B viruses co-circulated in 2019/20 in France [10] (see Supplement). Seasons with type B virus circulation can lead to a slow decay in incidence but a renewed increase is atypical [1]. The 2-week-long normal school holidays started between mid-February and early March depending on the region. While holidays may change the dynamics of influenza [9], this generally has an effect in the ascending phase of the epidemic rather than after the peak.