That's normally the "winter" vomiting bug isn't it? Lovely... think we had it once, not fun :/
Peaks late winter yeah, but always been a summer/warm autumn thing when it visited our household. Having kids is fun. Norovirus isn't stopped by alcohol gel, too.
If you want
a) a reason to keep wearing masks after 19/7
b) a reminder that nature is chaotically evil and wants us to suffer
we've just had our first "Norovirus - take care" email at work (NHS hospital) since December 2019