Novak Djokovic is battling the Australian authorities over permitting him into the country due to failing to meet their stringent entry rules regarding Covid-19 but he is not the only high-profile athlete to have been sceptical about the vaccine.
AFP Sport picks out five others:
The Green Bay Packers legend and Super Bowl winning quarterback has been a leading voice against vaccination.
The 38-year-old has cast himself in the role of a victim of a "woke mob" and "cancel culture" following criticism when he tested positive.
Prior to that he had said he was "immunized" having sought alternative treatment.