There are new COVID-19 restrictions for the 2021 U.S. Open, just as the tennis tournament is about to begin. Fans must now show proof of vaccination in order to attend the event, which wasn’t the case just prior to the start of the year’s final Grand Slam.

The U.S. Tennis Association announced Friday that proof of vaccination would be required for the USTA Billie Jean King National Tennis Center in Flushing Meadows, New York, where the tournament is scheduled to take place from Monday through Sept. 12. Prior to the announcement, vaccine proof was only needed to attend indoor restaurants located on the grounds.

Since Aug. 17, New York City law has barred unvaccinated adults from indoor entertainment venues, gyms and restaurants. The change in the U.S. Open rules came because the New York City mayor’s office ruled that Arthur Ashe Stadium is an indoor venue.

“Today, the U.S.T.A. was informed that the New York City mayor’s office will be mandating proof of Covid-19 vaccination for entrance to Arthur Ashe Stadium,” the statement said. “Given the continuing evolution of the Delta variant and in keeping with our intention to put the health and safety of our fans first, the U.S.T.A. will extend the mayor’s requirement to all U.S. Open ticket holders 12 years old and older.”

Arthur Ashe Stadium and Louis Armstrong Stadium will host U.S. Open matches at the National Tennis Center. Fans who plan to attend the U.S. Open must show proof of at least one COVID-19 vaccine dose.

Tickets had been on sale for several weeks without the stipulation that spectators would need to be vaccinated. People who previously bought tickets but no longer wish to attend the U.S. Open will be given refunds.

Last year’s tournament was held entirely without fans.

Venue for the 2021 US Open tennis tournament, from August 30 - September 12.
Venue for the 2021 US Open tennis tournament, from August 30 - September 12. AFP / Laurence CHU