Antibody vs. Antigen: Understanding The Pros And Cons Of Each COVID-19 Test

Whether you’re in need of an Antibody or Antigen test, understanding the pros and cons between each test equips you to help manage your health and control the spread of COVID-19.

Are you in need of an Antibody or Antigen test? What’s the difference between the two tests? Does Antibody tests show if you’re presently infected with COVID-19?

These are some common health question that beg to be answered with the on-going Coronavirus pandemic still in full swing with average number of daily deaths from COVID-19 in the U.S. climbing to above 2,600, according to the New York Times. Depending on your current situation there are a number of places to turn for testing – from clinics, to pharmacy store chains, and at-home testing – but first it helps to better understand the difference between the two tests. 

An Antibody test looks for the presence of a specific disease-causing organism by detecting antigens on the surface of cells or in body fluid. An Antibody test for COVID-19 involves taking either a nasal swab, saliva swab, or blood sample that looks for Coronavirus proteins using advanced imaging systems to determine if you’ve been exposed to COVID-19.

Antibody tests can also be used to detect pathogens – a bacterium, virus, or other microorganism that can cause disease. By using the body’s immune response against a pathogen, it’s possible to diagnose an infection prior to a person showing symptoms or signs of an illness. Essentially, an antigen test can reveal if you’ve been exposed to COVID-19, but does not show if you’re presently infected with the virus. If you test positive on an antibody test, you may have previously had COVID-19. If you test negative on an antibody test, you most likely have not had COVID-19. 

Compare and contrast that to an antigen test. 

An Antigen test looks for antibodies – proteins produced by the body’s immune system to fight pathogens – in a person’s saliva, blood, or urine. An easier way to think of an antigen is to imagine any substance your body does not recognize and tries to fight off.

Whereas an antibody test does not show if a person is currently ill with the virus, an antigen test can detect the Coronavirus and will indicate if you’re infected with COVID-19. If you are infected with the Coronavirus, antibodies in your blood will react with the antigens on the Coronavirus proteins in your saliva, causing them to clump together. Antigen tests have become widely popular due to their rapid result capabilities, with most showing results in 15 minutes or less. 

When your body becomes infected with a virus such as the Coronavirus, it produces antibodies designed specifically to bind to antigens like the spike proteins and helps your body get rid of the virus. Generally, these antibodies remain in the body over a long term to equip the body in fighting off future infections. 

If you test positive with the rapid Antigen test, you most likely have an active case of COVID-19. While false positives are possible and common, the most likely result and scenario is that you’ve become infected with the Coronavirus. If your test result is negative with the rapid Antigen test, you most likely do not have an active case of COVID-19. 

Whether you’re in need of an Antibody or Antigen test, understanding the pros and cons between each test equips you to help manage your health and control the spread of COVID-19.