Examine how things work among Bananarepublicans, and discover why they always seem to get it wrong.
1. Start with a fantasy: an existing drug will magically make the problem go away.
2. Advertise the fantasy.
3. Worry about evidence afterwards.
4. When the evidence comes back negative, ignore it and the damage it has done.
5. Never apologise or review the cause of the error.
6. Move onto the next fantasy.
There's no conversation to be had with someone who adopts that approach. For malaria drug, put Benghazi, trickle down economics, Seth Rich, Pizzagate, birtherism, etc etc. In the end, folks who work with facts can't be bothered to talk with fantasists.