We have written several blogs about COVID-19 antibody testing as of August 27, 2020. Still, the most common question we get is “so this lets me know if I have Coronavirus, right?” Our answer to that question is no—the test we have on-site only detects if you have had COVID-19.
We can’t fault anyone who asks this question. Antibodies and antigens are closely related. Antibodies develop in the body due to the presence of antigens.
Surface level issues also affect how most people think about the two words. Antibody sounds very similar to antigen, especially to those not involved in the medical field. Many advertisements or online listings simply say COVID-19 Testing, which further complicates the issue.
So, what are the differences between antibody and antigen tests? Let’s break it down.
Antibody Vs. Antigen
Antibodies and antigens are related but different. The definitions of each word do a great job separating them from each other.
An antibody is defined as “any of a large number of proteins.. that are produced normally by specialized B cells after stimulation by an antigen and act specifically against the antigen in an immune response.”
An antigen is defined as “a toxin or other foreign substance which induces an immune response in the body, especially the production of antibodies.”
These words are closely related, as antigens trigger the production of antibodies. This relation actually makes it easy to remember the definition of each word. Antigens come first (antigen tests confirm an active viral infection). Antibodies come second (antibody tests confirm the past presence of a viral infection).
Antibody Testing for COVID-19
COVID-19 Antibody tests detect the presence of specific antibodies in your blood. These antibodies develop to combat COVID-19, so their existence shows you have had COVID-19 in the past*.
The term Serology sometimes replaces the word ‘antibody’ on the websites and documentation of healthcare provides. COVID-19 serology testing is the same thing as COVID-19 antibody testing.**
Serology is defined as “the testing of a blood serum to detect the presence of antibodies against a specific antigen.” What this means in context is that any given COVID-19 serology test analyzes blood for the same antibodies as a COVID-19 antibody test.
*Studies about how long COVID-19 antibodies last are still ongoing.
**FDA Coronavirus Testing Basics Article
Antigen Testing for COVID-19
COVID-19 antigen tests check for the presence of the COVID-19 virus in your body. Unlike antibody tests, COVID-19 antigen tests require nasal or throat swab samples—not blood.
COVID-19 antigen tests are referred to as COVID-19 viral tests or diagnostic tests by many online healthcare provider listings. For all intents and purposes, COVID-19 Antigen Testing and COVID-19 Viral Testing are the same things.
You may want to do a bit more research into any provider that lists “COVID-19 Diagnostic Testing” as a service. Diagnostic is a broad word and you want to make sure you get the test you need.
COVID-19 Testing TLDR
For those in the “Too Long, Didn’t Read” category, check out this fantastic quick reference chart from the FDA Coronavirus Testing Basics Article:
Again—antigen tests detect current viral infections. Antibody tests detect past infections.
Antibody Testing at Oswald’s Pharmacy
We still offer COVID-19 Antibody tests several days a week. Our customers can schedule an appointment online or walk-in during testing hours. Our lab is CLIA certified and all of our technicians are licensed phlebotomists.
We are doing all we can to offer the goods and services our community needs during the COVID-19 Pandemic. If you have any questions or suggestions, send us an email or give us a call. We appreciate serving your needs!
