Thinking of getting the Covid antibody test?
Wondering if they are accurate??
Here are some of the current facts on this test.
- This test is not designed to detect active infection.
- False negatives do occur with the Covid antibody test.
“The reported rate of false negatives is 20%.” (1)
False negatives from Covid antibody test may result due to the following:
- It is too soon from exposure or actual disease. “It typically takes 1 to 3 weeks after infection or vaccination for your body to make antibodies. . . . Some people may take even longer to develop antibodies, and a small portion of people who are infected or vaccinated may never develop antibodies.” (2)
- The test may not detect antibodies developed from vaccination.
- The individual tested may have had a different strain that is not picked up with that particular antibody test.
What types of tests are used to detect Coronavirus antibodies?
- Binding antibody detection (can be a fingerstick or regular blood lab draw) (most common form of Covid antibody test to be performed)
- Neutralizing antibody detection tests (3, 4)
For detailed information on each test authorized to be performed (including sensitivity and specificity), visit this site. (Great information!)
For more in-depth reading, American Family Physician has an article with statistics concerning Cellex antibody test. (read here)
(1) From “Which Test is Best for Covid-19” by Robert Shmerling. https://www.health.harvard.edu/blog/which-test-is-best-for-covid-19-2020081020734#: Accessed 9/1/2021
(2) From “Test for Past Infection” from www.cdc.gov/coronavirus/2019-ncov/testing/serology-overview.html Accessed 9/1/21
(3) From “Interim Guidelines for Covid-19 Antibody Testing.” https://www.cdc.gov/coronavirus/2019-ncov/lab/resources/antibody-tests-guidelines.html Accessed 9/1/2021
(4) From “Covid-19 Antibody Testing.” https://www.mayoclinic.org/tests-procedures/covid-19-antibody-testing/about/pac-20489696 Accessed 9/1/2021.