What is antibody testing?
Antibody testing checks a sample of a person’s blood to look for antibodies to SARS-CoV-2, the virus that causes COVID-19.
These antibodies are produced when someone has been infected, so a positive result from this test indicates that person was previously infected with the virus.
The CDC does not know yet if the antibodies that result from infection with SARS-CoV-2 can protect someone from reinfection with this virus (immunity) or how long antibodies to the virus will protect someone. Scientists are conducting research to answer those questions.