protect the people around me. i was one of those very open people to follow what was going on. and when i got the opportunity to take advantage of it. >> not everyone feels that way, as i'm sure you know. even within the professional-sports world. >> reporter: some have been reluctant to share where they stand. >> me being available to my teammates on the floor is me taking care of my body. you know? me, you know, doing everything i can do to make sure i am available, both, mentally, physically, and spiritually as well. >> and do you mind me asking if you are confirming that you did get the vaccine? >> it's not -- it's not a big deal. >> reporter: and as the olympics begin in tokyo, notably without fans, several american athletes won't be there, either. after testing positive for covid-19. raising suspicions over whether they were vaccinated. swimmer, michael andrew, says he wasn't. >> i didn't want to put anything in my body that i didn't know how i would, potentially, react to. i didn't want to risk any days out. >> reporter: it is, still,