> I would say that if he tested negative, he would be unable to transmit infection so that part would be true.

This has not, to my knowledge, happened yet.

> I don't believe any sensible person believes that they become immune to all strains after recovering from one, and I do not believe that Trump was saying this. Do you?

I certainly do believe that the message trump intends to convey is that he is immune to the coronavirus and can no longer be re-infected period.