So what? The Government providing funds for the development of a vaccine and placing an advance order does not mean that Trump gets the credit for the creation of the vaccine. The American Government wasn't the only one doing that. Most European countries did the same. None of their leaders is desperately trying to claim the credit. The only one doing that is the narcissist in the White House.
Gosh, imagine that! A President taking credit for something that happened on his watch, something that he strongly urged and encouraged, and something that he facilitated by ordering the FDA to wave most of the senseless regulations that usually delay a drug's development and distribution by 1-5 years! Scandal! "Narcissism"!
He's never said he's the one who developed the vaccines, only that he deserves credit for pushing along the process, an entirely valid point.
And let's remember that when Trump said in October that a vaccine was just about ready and would be distributed early next year, Biden and Harris and other Democrats mocked, scoffed, and howled.