That would most likely be anyone diagnosed with Lupus. My better half is one who takes Plaquinel for Lupus and anecdotally she has not tested positive as ever having Covid.
A year ago, Dr. Oz was extremely enthusiastic about the use of HCQ for COVID-19. He was trying to find data on people suffering from lupus who had used hydroxychloroquine for years to see how many of these people had tested positive for COVID-19. Somehow that research got squelched and the needed information was never determined. Maybe it was just never publicized. There is so much evil politics involved in this pandemic.