One spokesman tonight said there is no evidence that HCQ prevents us from getting COVID. If people take it and don't get COVID I guess they could argue it was because of something else. I don't see how it is proven, except that in countries where people take it for malaria prevention, there would be fewer cases and we could review data on people in the US who take it for arthritis to see if there was fewer incidence of the virus, but that is only correlation, not really proof.