Infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) triggers a humoral immune response that generates antibodies against particular viral antigens such as the nucleocapsid (N) protein and spike (S) protein, including anti-S protein antibodies that target the spike’s S1 protein subunit and receptor-binding domains (RBD). Within days to weeks after an acute infection, serologic tests will detect the presence of these antibodies in serum. Serologic examination, on the other hand, should not be used to diagnose acute SARS-CoV-2 infection.

Serologic tests may classify people who have a resolving or previous SARS-CoV-2 infection, allowing scientists and public health experts to better understand the epidemiology of SARS-CoV-2 individuals and populations at higher risk of infection. Although the immune correlates of defence are not well known, evidence suggests that antibody production after infection likely confers some level of immunity against subsequent infection for at least 6 months. However, it is unknown to what extent emerging viral variants can influence immunity to