It's still not too late for anyone who is unvaccinated to get the vaccine! Hopefully the next administration undoes this change, but the really important part is managing to shrink the anti-vax movement (which, if you look at the data in my other comments, you can see has been a problem since before Trump).
Also, trump, as a representative, represents a large group of people. It's colloquial to refer to political parties by their leaders.
(And let's be clear: Operation Warp Speed was an enormous success even if Trump is an ignoramus)
Some of that might have been expediency — Biden was catching shit from the antivax and healthcare-skeptical movement and moving in on that would be easy — but Trump has always been vulnerable to being influenced by people and RFK Jr appears to be generally so much more persuasive than bears thinking about, so he was a factor later on.
Trump #2 (47) is fully an anti-vax presidency; even Hegseth backed away from flu vaccine mandates, only to have an outbreak in an Army (IIRC?) facility.