They’re testing for the efficacy of the drugs on the virus. They are apparently not testing for the effects of their new toys, screwing up ones immune system to the point of making them sicker than the virus would.
You are smug and happy with vaccines as they haven’t affected you. I would not wish my chronic form of Guillain–Barré on anyone. But it’s often a struggle not to, for people with blinders on.
Sometimes you misjudge. I have a 29 YO disabled son.