All COVID-19 antibody tests look for antibodies in the blood specific to the virus. There are antibody tests that look for one specific antibody (such as an IgG test). Other antibody tests look for the presence of multiple antibodies (such as a total antibody test). Both types of tests are helpful when trying to check if you have been exposed to the virus. At this time there is no advantage in checking for one antibody versus another. IgM and IgG antibodies are most useful when checking for past exposure to COVID-19. The CDC does not recommend testing for IgA antibodies.