It was especially prevalent, specifically with MAGA types, to claim they had already had Covid months before it was said to have first appeared. I talk to a lot of them in my line of work and I couldnt go a day in 2020 without one saying Im certain I had Covid back in June/July/August etc I just assumed they were dumbasses who conflated having a cough with having Covid, but who knows. Maybe it did originate in the US.