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.
Benedict Donald always takes credit for things he had nothing to do with just like Obama-Biden's economy that was the greatest on record before Benedict Donald destroyed it with his bogus Chinese tariffs and COVID-19 disaster. He had nothing to do with the vaccine because the drug companies said so.