Understanding Your COVID-19 Antibody Test Result

The COVID-19 Antibody Test is used to determine if your blood has antibodies to the SARS-CoV-2 virus, the virus that causes COVID-19. Antibodies may be found in the blood when the body is responding to or has responded to an infection, such as COVID-19. Antibodies may give full or partial immunity to the virus.

Antibodies to the virus that causes COVID-19 may be present as early as seven days after the onset of symptoms. Unfortunately, it may take as long as fourteen days after the onset of symptoms for antibodies to develop. To ensure more accurate test results, we recommend that you be tested for antibodies at least fourteen days after the onset of your symptoms.

Antibody testing is not used to diagnose current COVID-19 infection. For information about COVID-19 Active Virus Testing, please click here.



  • A POSITIVE antibody test result means it is likely you have had COVID-19 and that you have developed antibodies to the virus.
  • However, it is not known at this time how long your body will have these antibodies or whether they actually give you partial or complete immunity to future infections from the virus.
  • Also, there is a chance that a positive result could be a “false positive” result, in which case your body does not actually have any antibodies to the virus.
  • Therefore, even if you have a positive test result, we recommend that you continue to practice social distancing, wear a mask when in public, and wash your hands frequently.



  • A NEGATIVE antibody test result means that you have probably not developed antibodies to the virus and that it is unlikely you have had COVID-19.
  • It is possible to have a negative antibody test when, in fact, you have had COVID-19.  
    • You may have been tested too soon after you were infected before your body had a chance to produce antibodies.
    • Your body may not be capable of producing antibodies in response to the infection.  This is more likely to happen in patients whose immune system does not work properly or who are taking drugs that suppress the immune system.



  • Rarely, an equivocal result (neither positive nor negative) will be reported. This result could mean that you were tested too soon after infection. Another test seven days later is recommended if your result comes back as equivocal.


A positive, negative, or equivocal antibody test result does not have any relationship to contagiousness. You could have a positive, negative or equivocal antibody result and still be shedding virus and spreading the disease to others. Therefore, we cannot write a note for you to return to work certifying that you are not contagious based on your antibody result. We can only report the actual result.