Members of the Boston Red Sox take batting practice at Yankee Stadium on July 15. The game was postponed due to positive Covid-19 tests within the Yankee organization.
CNN  — 

Six players on the New York Yankees have tested positive for Covid-19, general manager Brian Cashman told reporters Thursday, in the second instance this year of breakthrough cases occurring among some members of the baseball team.

“We have three positives, and we have three pending that we’ve had rapid tests on,” Cashman said, saying the three positive rapid tests are being confirmed with additional lab work.

The players with confirmed positive tests are pitchers Jonathan Loaisiga, Nestor Cortes Jr. and Wandy Peralta, according to the team. The three unnamed players have results pending.

The three named players were all vaccinated, according to the team. Two of the players received Johnson & Johnson vaccines and the other was from either Pfizer or Moderna, Cashman says.

The pitchers are “doing well thus far,” Cashman said, while he declined to comment on the unnamed players until final confirmation of their positive tests are received by the team.

Earlier this season, eight positive tests were recorded among coaching and travel staff, all of whom had previously taken the Johnson & Johnson vaccine. Of the team members who tested positive, only one showed mild symptoms and his condition improved, the Yankees said.

A ninth positive test, from infielder Gleyber Torres, was later determined to be a false positive, according to Yankees manager Aaron Boone.

Occasional breakthrough cases are not unexpected because no vaccine is perfect.

The J&J one-shot vaccine was found in earlier US clinical trials to be 72% effective against moderate Covid-19 and 85% effective against severe Covid-19. Pfizer and Moderna vaccines were 90% effective at preventing infections following full vaccination, according to a March report from the US Centers for Disease Control and Prevention.

Thursday’s game between the Yankees and Boston Red Sox was postponed due to the positive tests.

On Friday, MLB stated that additional testing and contact tracing had concluded, allowing Friday’s game between the two teams at Yankee Stadium to be played.