It's more like he compressed the vax phase in period that Fauci wanted kept at 4 or 5 years. Just enough to fuck up a Trump 2nd term.
A vaccine was already out there, developed via HIV research. It wasn't a big deal to retool. One of my kids knows some of the researchers for one of the vaxxes. Kid says it was no biggie, and I'm guessing Trump heard the same, so he walked over Fauci's rollout plan.
Go with the theory that viruses, or pathogens in general, become more infective but less virulent as they mutate. It could be the vaccine Trump was shown was very effective against the original virulent strain.
The variants will infect more, and there will still be deaths because the incidence number is higher. For example, using make up numbers for clarity, if the original pathogen killed 5% of those it infected and the new variants kills 1% but infects 5x as many people you will have as many Covid deaths.
The survival rate is a lot higher, though, and assuming the vaccine itself still kills at the same % rate the risk of dying from the vaccine but not Covid becomes a lot higher when controlled against just the variants.
It may may be the original virus still out there, too. So the presumed benefit of the original vaccine against that strain is still present. You just don't need it for the variants. Might be Trump's take, not sure.
Very likely we're looking at a situation where Fauci's boys are using the variants as plan B after Trump fucked up their 5 year original vax rollout plan.