Back to Tests & Procedures

COVID-19 antibody testing

COVID-19 antibody testing is a blood test. The test can provide information about how your body reacted to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 is the name of the virus that causes coronavirus disease 2019 (COVID-19). It also can show how your body reacted to COVID-19 vaccines. Antibody testing also is known as serology testing. A negative serology test means no antibodies were detected in your blood.

An antibody test can’t find out whether you’re currently infected with the COVID-19 virus. And antibody tests shouldn’t be used to see if you’re protected from COVID-19. An antibody test also won’t tell you if you need a vaccine.

Your immune system makes antibodies in response to an infection. Your immune system involves a complex network of cells, organs and tissues. This system identifies foreign substances in your body. And it helps clear out infections and diseases. After infection with the COVID-19 virus or a COVID-19 vaccine, your body can take 2 to 3 weeks to make enough antibodies to be found in an antibody test. So it’s important that you’re not tested too soon.

Antibodies may be remain in your blood for many months. These antibodies are thought to give some form of immunity to the COVID-19 virus. But there’s currently not enough evidence to know how long the antibodies last. More research also is needed to know how much past infection with the virus helps protect you from getting another infection. Studies are ongoing to learn more about COVID-19 antibodies as well as other parts of the immune system.

Antibody tests may find some types of antibodies related to the COVID-19 virus:

Antibody testing for COVID-19 may be done if:

If a child is sick and the health care provider thinks it’s multisystem inflammatory syndrome in children (MIS-C), the doctor may order antibody testing. This test can help diagnose MIS-C. Many children with MIS-C have antibodies to the virus that causes COVID-19, showing past infection with the coronavirus.

If you’re interested in having a COVID-19 antibody test, contact your care provider or your local health department. Whether or not you’re eligible for testing may depend on the availability of tests in your area and local or state health department guidelines.

Results of COVID-19 antibody tests may not always be accurate. Results may not be accurate if the test was done too soon after infection or the test quality is uncertain. At the start of the pandemic, there was a rush to get antibody tests on the market. Now the U.S. Food and Drug Administration posts data online about the performance of some antibody tests. The results may vary based on which strain of the virus is spreading in your area.

COVID-19 antibody testing could lead to false-positive or false-negative test results:

Your doctor or testing center will tell you where to go for testing and how the test will be done. Ask if you, and anyone who comes with you, need to wear a face mask to and from the testing center.

To do a COVID-19 antibody test, typically a member of your health care team takes a blood sample. It’s taken by a finger prick or by drawing blood from a vein in your arm. Then the sample goes to a lab for testing to find out whether you’ve developed antibodies against the COVID-19 virus.

COVID-19 antibody test results may be ready the same day as your test at some sites. Other places may have to send test samples out to a lab for testing. So results may not be ready for a few days.

COVID-19 antibody test results could be:

People who have had COVID-19 or tested positive for antibodies shouldn’t assume they’re protected from getting a COVID-19 infection again. Reinfection is known to occur. Researchers are trying to find out how much protection antibodies provide against the COVID-19 virus, what the level of protection is and how long immunity may last.

Until there is more information, even if your test results show that you have COVID-19 antibodies, keep taking steps to avoid the risk of spreading the virus. This includes getting vaccinated, avoiding close contact with anyone who is sick or has symptoms, and washing your hands often.

© 1998-2024 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved.

We Make Health Possible

As East Central Indiana’s population grows, we’re putting health care where people need it most. Besides Hancock Regional Hospital, ranked as one of the nation’s safest by the Lown Hospital Index, our network includes more than 30 other locations near your home or work.

Learn More about Hancock