FILE - Fans of Serbian tennis star Novak Djokovic react outside Federal Court ahead of the Australian Open in Melbourne, Australia, Monday, Jan. 10, 2022. Athletes have been put at center court of arguments over COVID vaccines. The NFL's Aaron Rodgers, the NBA's Kyrie Irving, and tennis's Novak Djokovic, have each become cultural touchstones in the cultural controversy. (AP Photo/Hamish Blair, File)