(Reuters) — Media and other in-person league personnel functioning in near proximity to teams and players on game day are under a new mandate from the NBA to receive the COVID-19 booster shot by Jan. 5.

In a memo to NBA executives and the league board of governors, senior vice president for player matters David Weiss outlined the updated protocol. It applies to all non-player personnel eligible to receive a third dose of the COVID-19 vaccine as outlined by the Centers for Disease Control and Prevention.

The order covers “league staff and vendors who in their official capacities interact in person with any player” within 15 feet, including referees, league operations, player development, team and player marketing, communications and NBA photos.

Teams were informed to monitor the process and report issues directly to the league by Jan. 7.

The shift follows comments from commissioner Adam Silver on Tuesday in an interview with ESPN during which he said data and medical advisers collectively point to very low virus transmission in persons with three doses — two mRNA shots and the booster. Silver said those with three doses are not “shedding the virus” based on gene testing the league has reviewed after positive tests.

In the Wednesday release, the NBA said the decision was made “based on discussions with the NBA’s infectious disease and other medical experts, CDC guidance, and initial data showing substantially reduced protection from the omicron variant absent a booster.”

A nationwide spike in COVID-19 cases has hit the NBA hard in December after only 17 positives in October and November combined. More than 115 positive tests were recorded in players in the first 21 days of the month.

Silver said games would be played as planned unless roster size dictates postponement, as was the case with postponed games on Wednesday (Toronto Raptors at Chicago Bulls) and Thursday (Brooklyn Nets at Portland Trail Blazers).