Test for Past Infection (Antibody Test)
- What do your results mean? If you test positive / If you test negative
Published by:
Centers for Disease Control and Prevention (CDC), updated 30 June 2020
https://www.cdc.gov/coronavirus/2019-ncov/testing/serology-overview.html
From the article:
What do your results mean? If you test positive
* A positive test result shows you may have antibodies from an infection with the virus that causes COVID-19. However, there is a chance a positive result means that you have antibodies from an infection with a virus from the same family of viruses (called coronaviruses), such as the one that causes the common cold.
* Having antibodies to the virus that causes COVID-19 may provide protection from getting infected with the virus again. If it does, we do not know how much protection the antibodies may provide or how long this protection may last.
* Talk with your healthcare provider about your test result and the type of test you took to understand what your result means. Your provider may suggest you take a second type of antibody test to see if the first test was accurate.
* You should continue to protect yourself and others since you could get infected with the virus again.
> If you work in a job where you wear personal protective equipment (PPE), continue wearing PPE.
* You may test positive for antibodies even if you have never had symptoms of COVID-19. This can happen if you had an infection without symptoms, which is called an asymptomatic infection.
What do your results mean? If you test negative
* You may not have ever had COVID-19. Talk with your healthcare provider about your test result and the type of test you took to understand what your result means.
* You could still have a current infection.
> The test may be negative because it typically takes 1–3 weeks after infection for your body to make antibodies. It’s possible you could still get sick if you have been exposed to the virus recently. This means you could still spread the virus.
> Some people may take even longer to develop antibodies, and some people who are infected may not ever develop antibodies.
* If you get symptoms after the antibody test, you might need another test called a viral test.
Regardless of whether you test positive or negative, the results do not confirm whether or not you are able to spread the virus that causes COVID-19. Until we know more, continue to take steps to protect yourself and others.