How Does COVID-19 Antibody Testing Work?

coronavirus antibodies

If you tested positive for COVID-19 or strongly believe that that you may have had it, you might want to get an antibody test to see if you could have some immunity to reinfection. Unfortunately, a positive antibody test result does not mean you are 100% safe from reinfection, but it could have you sleeping a bit easier at night.

Here is how the test works and why you might want to consider getting one. 

What are antibodies?

Antibodies are created by your body's immune system as it fights a virus, and they will fuse to the antigen of the virus to disarm it. After you recover, antibodies remain in your system so that if the virus strikes again, your body is ready to fight it. However, it's still too early to know how long COVID-19 antibodies live in our body and how effective they are at disarming the virus again. 

How does the antibody test work? 

While a test may be hard to find, your doctor or local hospital should be able to help identify where you can get one. If you get an antibody test, it will likely be a finger prick. In the lab, the blood is exposed to the antigen of the virus to see if the antibodies remember it. If there are antibodies in your blood, they will stick and bind to the coronavirus.

Please note, an antibody test is not diagnostic. It will not tell you if you currently have coronavirus, it can only identify if you previously had the virus. Antibodies do not form in the body until 1-3 weeks after you have been exposed to the virus. However, a person could still be infectious even though they feel fully recovered. Please see the CDC's recommendation for when you are likely no longer infectious to others. 

Scientists do not yet know if antibodies in the blood mean that a person is safe from reinfection, but it's likely to provide a person some level of protection. If you do get a positive antibody test result, please be aware that false positives are possible and adhering to social distancing is still necessary. If your antibody test is negative, it's likely that you never had the virus. 

Why getting an antibody test could help

Antibody tests can tell scientists how common COVID-19 is. Once they know who has had the virus they can figure out how sick it makes most people. They can also find out what happens to people who get re-exposed to it again. This can help them start to understand who is immune to the virus. 

If you've tested positive for COVID-19, or suspect you had it, and have fully recovered, you might want to get an antibody test. If you have antibodies, you might want to consider donating plasma to the National COVID-19 Convalescent Plasma Project to help others battling the virus.