It's too late now, but the US could have provided vaccines for every athlete, coach, team support, whatever, for every person from every country competing in the games. Plus all the reporters and Olympic staff too.
Use that US excess supply. Sure, it could be argued that instead of this we should give doses to countries in need and better targeted. But, in the scope of US supply and donations to other countries, would this number of doses really matter that much? What is it, 20K people?
Think of the marketing opportunity. US Official Vaccine Sponsor of the 2020* Olympics. They could have run ads galore with all the different teams and countries about how great getting the vaccine is. Be like superstar/team/underdog/touching story athlete and get your vaccination today!
Before someone says "US Vaccine Contracts prevent this", which vaccine provider wouldn't want the positive press of being an Olympic Vaccine supplier or more importantly, which would want the bad press of denying vaccine to Olympic athletes.
The Olympic committee would probably want a check to use that marketing.
Hindsight is wonderful, a missed opportunity.