The results of the league-wide COVID-19 antibody test are in, and only 60 out of 5,754 participants from MLB tested positive for antibodies.
You can read about the test here and here, among other places, but the short version is that Stanford was trying to conduct one of the largest antibody tests from a geographically large range, and Major League Baseball volunteered to participate.
Lead researcher Dr. Jay Bhattacharya, a professor of medicine at Stanford, expected more positive results.
“I was expecting a larger number of people to test positive,” Bhattacharya said, per The Athletic. “These numbers indicate these numbers haven’t spread very far. But at the same time, we have had a zero percent mortality rate.”
The modest 0.7% implied rate of infection is, I suspect, much lower than anyone was expecting, even given the tests being conducted in mid-April. Experts have estimated that 2 to 5% of the US population has been infected. For what it’s worth, 70% of the positive tests were for people who had not showing symptoms of the illness.
A reminder: this testing process had nothing to do with a return to baseball, or even a specific interest in COVID-19 and athletes or sports leagues. It was simply the case that MLB was in a unique position to have infrastructure in place for a diverse group of people to participate very quickly in a test. Thus, the results have no specific bearing on sports one way or another.
As for the broader implications of the test, it’s the first antibody test that I’ve seen that indicated a much *lower* rate of infection than we were previously thinking. Tests in Santa Clara, New York, and elsewhere suggested far more people had been infected than confirmed test results would show, which would indicate a much higher rate of asymptomatic carriers, but also a much lower mortality rate. I’ll leave the conclusions to the experts, but it sure seems like this is a mixed bag, at best.
As Bhattacharya told ESPN: “It’s very clear that the epidemic is still in the early stages throughout the country.”