“I was expecting a larger number,” said Dr. Jay Bhattacharya, a professor of medicine at the University of Stanford, which ran the study. “It shows the value of doing the science as opposed to guessing.”

The results of the study, which was held in mid-April, revealed a prevalence of COVID antibodies in the MLB employee population of 0.7 percent — a number adjusted to reflect testing accuracy. The survey showed that about 70% of those who tested positive for COVID antibodies had been asymptomatic.

Twenty-six of MLB’s 30 teams participated in the study, which sent out 10,000 test kits. Because of stay-at-home orders and other logistical complications, 5,754 of the tests, in which participants use a pin prick to draw blood and received almost-immediate results, were completed. A total of 5,603 completed the tests and filled out a survey that accompanied it.