Just as the real effect of a vaccine ban will be to damage US health, and the real effect of dismantling government funded R&D will be to damage US education and competitiveness.
I have no doubt some people believe patriotism is involved, and some large companies will get exemptions.
But I also have no doubt these decisions aren't being made for the long-term benefit of the US as a whole. Or even most of it. Or even those parts of it which are currently exempt.
This is Brexit++, sponsored by the same people, with similar - but much worse - lasting effects.