I took Plaquenil for 15 years at 200 mg twice a day. I quit a couple of years ago because my symptoms (joint inflammation) went into remission. Don’t know if I have any residual still in my system or not.
You’re right, it would be an excellent study to see if ( present or past) users of Plaquenil were getting protection from COVID -19 infection. Very interesting indeed.
I thought I heard someone say that the rate of infection in third world countries who have experienced malaria outbreaks is almost negligent. Could that be a reason?