Serologic test results should not be used to make decisions about returning persons to the workplace, according to the new guidelines on COVID-19 antibody test published on the website of the U.S. Centers for Disease Control and Prevention (CDC).

Antibody test can play an important role in understanding the virus's epidemiology in the general population and identifying groups at higher risk for infection, according to the CDC.

Unlike viral direct detection methods that can detect acutely infected persons, antibody tests help determine whether the individual being tested was ever infected, even if that person never showed symptoms.

"Antibodies in some persons can be detected within the first week of illness onset," the CDC said.

The presence of antibodies may decrease a person's infectiousness and offer some level of protection from reinfection. However, definitive data are lacking, and it remains uncertain whether individuals with antibodies are protected against reinfection with SARS-CoV-2, the virus causes COVID-19, according to the CDC.

"Serologic test results should not be used to make decisions about grouping persons residing in or being admitted to congregate settings, such as schools, dormitories, or correctional facilities," said the CDC.

"Serologic test results should not be used to make decisions about returning persons to the workplace," said the CDC.

It cannot be assumed that individuals with truly positive antibody test results are protected from future infection, according to the CDC.