Antibody tests have offered hope for progress against the coronavirus because they may help understand the outbreak and help society return to normal.
Studies of the tests, which look for COVID-19 antibodies that indicate a person has recovered from the virus, have ramped up this month.
The National Institutes of Health announced that it would begin recruiting as many of 10,000 volunteers for a study of the tests, and Major League Baseball said its employees would participate in a similar study conducted by Stanford University.
The Centers for Disease Control and Prevention also began a preliminary study of antibodies this month.
Here's what you need to know about antibody testing.
