An antibody test cannot determine whether you’re immune from COVID-19 following a vaccination. COVID-19 vaccines help your body produce antibodies to fight infection from the virus that causes COVID-19. However, not all antibody tests are the same, and some tests can only detect certain types of antibodies. If you get an antibody test after receiving a vaccine, you may or may not test positive for antibodies depending on the test.
Additionally, antibody testing should not be used to diagnose a current COVID-19 infection, as it can take 1 to 3 weeks after the infection for your body to make antibodies.