In December and January, it is entirely possible that they were diagnosed as the flu, when it actually was covid-19 and the doctors just attributed to the flu.

This could have been in our population for a long time.

I am not an expert, nor do I play one on TV. But if this went unchecked for so long in China, it most likely has been here for a while, and there is a good segment that has had it, recovered and now immune.

In Jan, my son had a cough that persisted for a couple of weeks,.....my daughter had a sore throat and a cough for a few week in Feb.