What do you mean? Why wouldn't that be regarded as the good thing about his management of the pandemic?
Warp speed was a good thing. So how is it that Trump managed to fuck it up. Complicated unless you look at Trump from the start.
Trump's failure is that at the same time that he signed off on the vaccine production he began to construct the political position that:
1. Downplayed the severity of the pandemic in the face of overwhelming evidence.
2. Delayed while obfuscating the federal (non) response to the pandemic.
3. And most importantly, he sewed the seeds of distrust that made a large percentage of the population distrust the very vaccine of which he wishes to be proud.
Do you see that? They produced the vaccine and now 40% of his party faithful refuse to take it. This puts all of us in danger. Even those of us who have been vaccinated.
Here is the reality. We are doing a terrible job of putting this vaccine into arms in a great many countries. (Including the USA because of refusal to take it.) Every person who gets the virus, symptomatic or not, has the potential to spawn a variant that defeats vaccination or if frightfully more virulent. Because Republicans, it is entirely possible that the variant that wipes out the next three million people will be the "Alabama variant".
So Trump can't take credit for heroism in simply placing an order for vaccines. There are about 400,000 Americans dead today because of his failures. When I was a kid there was talk of something very much like this. Of Hitler we often said, "Yes. But he make the trains run on time".