On Tuesday, an official from the World Health Organization (WHO) said that asymptomatic spread is "a major unknown," and the consensus on whether people can spread coronavirus without symptoms is currently unclear.
An upcoming study intends to help clarify if coronavirus can be spread by asymptomatic people by measuring how many adults in the United States the virus has infected without them knowing or showing symptoms.
The study is being led by the National Institutes of Health (NIH), the University of Alabama at Birmingham and the University of Pittsburgh.
Researchers will analyze blood samples from 10,000 adults to see if they have antibodies to the virus — indications of a prior infection, according to a press release. All participants must confirm that they have never been diagnosed with COVID-19.
Results are expected to come back by the end of the summer, and researchers hope that the study will also inform our understanding of "herd immunity," which is when a majority of the population is immune to the virus.
In the press release, Eric Ford, one of the lead researchers and a professor at the University of Alabama School of Public Health, said, "absent a vaccine, we want to reach herd immunity. For most diseases, 50 percent of the population needs to have been exposed; but with the infection rate of COVID-19, 65 to 70 percent of the population needs to be exposed to build up herd immunity."