Abstract
Individuals who have been vaccinated for COVID19 should have IgG antibody in response to the specific antigen that is the target in the vaccine development. There are several options for targeted COVID19 antigen, but most manufacturers have focused on the spike protein. Using our understanding of the targeted antigen for vaccine development, we can develop testing algorithmic scheme for anti-spike and anti-nucleocapsid antibody assays to aid delineation of infection versus vaccination in our patient population. Clear communication from laboratories specifying the specific SARS-CoV-2 antibodies (i.e., anti-spike, anti-nucleocapsid, or both) in their antibody tests at both the ordering and reporting levels will play crucial role in the development of this approach and is essential to avoid potential provider/patient confusion in the interpretation of serologic testing.