Sometimes its easier to believe in lies than it is the reality of what is before you. The numbers here in the US are just so damn staggering that many of us know someone - even if only tangentially - who was seriously ill for a time, and could have died. I have family members who are normally logical, intelligent people; but believe the entire thing is fake, or that the Chinese created the virus for germ warfare.
While I was young, I remember the AIDS epidemic, about how people were scared shitless that they'd get it from shaking someones hand, or conspiracy theories that the government created the virus to kill off gay people, or the racists of the day who said some African immigrant had sex with a monkey and brought it to america. I remember family members who just staunchly refused to believe it was real, until I had people in my own little rural school with HIV (my graduating class was only 52 people). I also remember a president who refused to do anything about it until the public outcry become so fierce he had no choice.