Coronavirus (COVID-19) antibody testing is a blood test that can detect the presence of antibodies to the SARS-CoV-2 virus, which causes COVID-19. Antibodies are proteins that the body produces in response to infection. They help the body fight off infection and protect against future infection.
COVID-19 antibody tests can be used to:
- Determine if someone has been exposed to the SARS-CoV-2 virus in the past
- Identify people who have had COVID-19 but may not have experienced symptoms
- Assess the effectiveness of COVID-19 vaccines
COVID-19 antibody tests are not used to diagnose current COVID-19 infection. It takes several days or weeks for the body to produce antibodies after infection, so a negative antibody test result does not necessarily mean that someone is not infected with COVID-19.
There are two main types of COVID-19 antibody tests:
- IgM antibody tests: IgM antibodies are produced early in the course of infection. A positive IgM antibody test result indicates that someone has been recently infected with the SARS-CoV-2 virus.
- IgG antibody tests: IgG antibodies are produced later in the course of infection and can persist for months or even years after infection. A positive IgG antibody test result indicates that someone has been infected with the SARS-CoV-2 virus in the past.
COVID-19 antibody tests are available at many doctor’s offices, pharmacies, and other healthcare facilities. They are typically covered by insurance.
If you are considering getting a COVID-19 antibody test, talk to your doctor about whether it is right for you. They can help you to understand the results of the test and how to interpret them.