I think Covid-19 is still a huge deal... I don't know anything about medical anything, but my understanding is that it attacks your blood vessels and your immune system - so now the flu and whatever else is knocking us all for six. I don't know how you're going, but everyone I work with gets sick like every month or two, especially families with school-aged kids. In the US, Thanksgiving/Christmas time is brutal, literally everyone gets sick.
Apparently 10% of people end up with LongCovid, which basically means the symthoms hang around for weeks or months afterwards.