Two preliminary, antibody-based studies in different parts of California suggest the SARS-CoV-2 virus might be circulating more widely than previously thought, but both studies — neither of which have been peer-reviewed — have come under criticism.
Stanford University researchers collected blood samples from 3,300 residents of Santa Clara County in Northern California to estimate that between 2.5 percent and 4.2 percent of residents there had coronavirus antibodies in their blood in early April, the Los Angeles Times reports. The LA Times notes that the county had about 1,000 reported cases at that time, but that this analysis would suggest there were between 48,000 and 81,000 cases.
An early-stage antibody-based study by Los Angeles County and the University of Southern California — which shares some authors with the Stanford-led study — similarly estimates that about 4.1 percent of adult residents there had antibodies to the virus, the Associated Press adds.
But as Wired reports, there may be problems with both the studies' methods and the test they used. The Stanford study, for instance, recruited volunteers via social media and may not be representative. Additionally, Scripps Research's Eric Topol tells the AP that the tests used by the studies have not been well validated and may overestimate the number of people with antibodies.
"The problem is they've given a false sense that this is not a bad virus after all," Topol tells the AP. "It's bad math, bad tests, and bad outcomes for the confusion that it engenders."