(WFLA/CNN) – Those antibody tests for the coronavirus may not be as reliable as previously thought.
The Centers for Disease Control and Prevention released new guidance saying antibody tests used to determine if people have been infected in the past with COVID-19 might be wrong up to half the time.
Antibody tests, often called serologic tests, look for evidence of an immune response to infection.
While the antibodies can be detected in some people within the first week of the onset of the illness, the tests are not accurate enough to use to make important policy decisions, like within schools, dormitories, or correctional facilities.
The new guidance, which is on the CDC’s website, says health officials or health care providers who are using antibody tests need to use the most accurate test they can find and might need to test people twice.
The new CDC guidelines echo advice from the Food and Drug Administration and the University of Minnesota urging caution about the test results.