COVID-19 Antibody Testing

Michigan Medicine offers COVID-19 (SARS-CoV-2) antibody testing to support the determination of whether an individual has had the COVID-19 virus in the past.

Antibody tests, also known as serology tests, detect antibodies in the blood. Antibodies are generated by the body as part of an immune response. Immunoglobulin G (IgG) is the most common type of antibody in your blood and other body fluids. An individual with COVID-19 antibodies likely has been infected with COVID-19 in the past. Antibodies can usually be detected in a person’s blood 2-3 weeks after symptoms begin. 

By contrast, standard nasal swab testing (molecular PCR tests) are the first line of testing to determine if a person has an active COVID-19 infection.

Michigan Medicine antibody testing methods have been rigorously validated, and have a greater than 95% sensitivity at greater than two weeks after symptom onset.  Michigan Medicine testing methods also demonstrate greater than 98% specificity.

Questions and Answers About Antibody Testing

What does COVID-19 antibody testing include?

COVID-19 antibody testing is done through a blood draw.  A single tube of blood is needed for the test, and can be drawn along with other blood work if appropriate. Antibody testing can be done for individuals at any of our blood draw locations as well as for inpatients in our hospitals, when appropriate.

Test results are generally available within 1-2 days.

Who can receive COVID-19 antibody testing at Michigan Medicine?

You must have a laboratory test order from a Michigan Medicine provider to be tested for COVID-19 antibodies at Michigan Medicine.

Antibody testing is available for adult and pediatric patients. Indications for COVID-19 antibody testing at Michigan Medicine include:

  • Evaluation of a patient with possible prior COVID-19 infection who is at least 14 days out from acute symptoms or illness, especially those patients not able to get a COVID-19 (Molecular PCR) test during that symptomatic period.
  • Evaluation of a patient with unexplained COVID-19-like symptoms to determine if those symptoms may have been caused by COVID-19.
  • Identifying potential COVID-19 convalescent plasma donors

Antibodies are not produced in the early stages of an infection.  For that reason, antibody testing is not appropriate as a test for patients currently experiencing acute symptoms of possible COVID-19.

Molecular PCR testing (also available at Michigan Medicine through your Michigan Medicine health provider) is the appropriate test for diagnosis of acute illness.

How can I get COVID-19 antibody testing at Michigan Medicine?

You must have a laboratory test order to be tested for COVID-19 antibodies. Contact your Michigan Medicine provider to ask if antibody testing is right for you.  Any Michigan Medicine provider can order antibody testing for a patient who meets the testing indications.

What do COVID-19 antibody test results mean?

A positive COVID-19 antibody test result means IgG antibodies specific to the SARS-CoV-2 virus are present in your bloodstream, indicating likely prior COVID-19 exposure and infection.

A negative result indicates IgG antibodies to SARS-CoV-2 were not detected, which could be due to either absence of prior infection, testing too soon after an infection or an immunocompromised state.

There is currently no conclusive evidence that the presence of antibodies means a person will be protected from or immune to a future COVID-19 infection. Antibody test results do not lessen the importance of social distancing or use of cloth face covers or masks.

Is COVID-19 antibody testing covered by insurance?

Contact your insurance provider to determine if antibody testing is a covered benefit under your health plan.

For Community Providers

Our provider colleagues can have their patients tested for COVID-19 antibodies through a referral to Michigan Medicine Laboratories (M-Labs).