No, the vast majority of Americans think covid-19 is real. Vox had a poll saying it was in the area of 1%. The issue is many don't want to be forced to wear masks, which is dumb and selfish, but not what you are saying.

Meanwhile as of 2019, over 20% of Americans doubt climate change, a much more significant number. This is far too high in my opinion, but it is steadily improving.