There are some people who don't know any better and they will take his advice not to get an antibody test, before they get a shot. The writer is simply pointing that out.If that's the point the writer's trying to make I hope he isn't relying on his writing skills to make a living.
The article didn't get within hailing distance of that explanation.
I'm really not sure why you are having difficulty with the author criticizing Fauci's bad medical advice?
Seems pretty straight forward.