SAN FRANCISCO (AP) — The San Francisco Giants and Arizona Diamondbacks are two of the Major League Baseball teams participating in a study of the coronavirus that will test hundreds of people — including players — from the various clubs for antibodies.

Both Arizona and San Francisco confirmed they were participating.

The Oakland Athletics also are taking part, a person with direct knowledge of the club's decision told The Associated Press on Tuesday, speaking on condition of anonymity because specific details weren't made public. Stanford University is one of the institutions running the study.

Which employees are in the study varies by teams, the person said without offering specifics on who with Oakland had been tested.

Another person with knowledge of the study said each organization decided who would be tested, such as front-office executives, full-time employees or players — who were given the option to participate.

The A's have been affected by COVID-19, with minor league manager Webster Garrison on a ventilator in a Louisiana hospital to treat the virus. His fiancee, Nikki Trudeaux, posted Monday he still was using the ventilator but she was able to see his eyes thanks to a nurse who helped them connect through a video call.

For most people, the new coronavirus causes mild or moderate symptoms, such as fever and cough that clear up in two to three weeks. Older adults and people with existing health problems can experience severe illness, including pneumonia and death.

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