About Our COVID-19 Tests

Our Statement on Serologic Testing (Blood Testing) for COVID-19 Antibodies

April 28, 2020

Summary

  1. These tests are new. The meaning of the results is not yet fully understood.
  2. A positive test may not mean you are protected from the virus in the future or that you are no longer infectious.
  3. A positive test may not mean you were infected by COVID-19 virus; it may detect antibodies to coronaviruses that cause the harmless "common cold," to other viruses, or simply be false ("falsepositive").
  4. A negative test does not mean that you have not been exposed to the virus or that you cannot infect others.
  5. The results of this test should not be used to decide if you can safely return to work.
  6. It is not clear that insurance or Medicare/Medicaid will pay for this testing, and you may be liable for payment.

Further study may identify the most useful test in the future, but currently we don’t know which test will provide the best information. We will continue to follow track improvements and share information.

Sources

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Frequently asked questions

  • What are antibodies?

    Antibodies are proteins made by your body’s immune system to fight viruses. These antibodies are attacking specific places on the surface of the virus.

  • What if the antibody test is positive?

    A positive test means that you may have been exposed to the virus causing COVID-19 (SARS-CoV-2). It is possible some of the tests are going to detect other viruses that are common in the community or simply be falsely positive. If you have had an illness compatible with COVID-19 infection, a positive test is more likely to be correct.

  • If I have antibodies to SARS-CoV-2, does that mean I won’t get COVID-19 in the future?

    Not necessarily. We don’t know yet which antibodies protect against getting COVID-19. In addition, some people making these antibodies still have virus in their nose, suggesting they could still be infectious.

  • Does everyone make antibodies to the virus causing COVID-19?

    No. Not all people make antibodies to the virus. The current information suggests that up to 2% of people who had COVID-19 do not make antibodies. Some of these people have weaker immune systems, but some people have normal immune systems and had only mild symptoms of COVID-19.

  • Are all the tests for antibodies the same?
    No. The tests offered in labs and tests across the country are all different. They are looking for different kinds of antibodies recognizing different structures on the virus. Therefore different tests are not equally good at picking up antibodies. The Food and Drug Administration (FDA) has been issuing Emergency Use Authorization to test companies. Emergency authorization means that the FDA and the companies making the tests have not done the comprehensive studies that are normally required before selling to the public or medical professionals.

Fact sheets for patients