French doctor and virologist Didier Raoult, whose use of malaria medication hydroxychloroquine at a treatment for Covid-19 has attracted worldwide attention and controversy, was to respond to questions of a parliamentary committee investigating France’s response to the epidemic. The inquiry of 32 lawmakers from different political parties was launched last month to “learn lessons” about France’s handling of the Covid-19 epidemic. After looking into face masks, the panel was to turn to hydroxychloroquine, a malaria medication championed as a treatment for Covid-19 by Raoult, who was to respond in late afternoon. “What we want to understand from Mr. Raoult is...