A mere 0.7 percent of people tested positive for Covid-19 antibodies, Major League Baseball (MLB) learned after it recently conducted the largest coronavirus-related antibody study in the US.

Just 60 of the 5 603 MLB employees tested positive for coronavirus antibodies, said Stanford University doctor Jay Bhattacharya.

Bhattacharya, a professor of medicine at Stanford University, said that based on previous smaller studies he had seen, he expected the MLB number to be much higher.

"It's very clear that the epidemic is still in the early stages throughout the country," he said. 

"I was expecting a larger number. It shows the value of doing the science as opposed to guessing."

The survey also showed that about 70 percent of those who tested positive for Covid-19 antibodies had been asymptomatic.

Twenty-six of MLB's 30 teams participated in the study, which sent out 10 000 test kits. Participants used a pin prick to draw blood and received almost immediate results.

There was no information on how many players participated in the study.

The Arizona Diamondbacks returned the most tests, 362, while the Los Angeles Angels had the highest positive rate among the 123 tests submitted by their team. No details were given on the exact number of positives.

Four teams declined to take part.

Bhattacharya said interest in the MLB study was high among the medical community.

"I've never gotten so many emails in my life about the results of a study before," Bhattacharya said. "There was a huge amount of public interest."