The role of antigen availability during B cell induction and its effect on sustained memory and antibody production after infection and vaccination-lessons learned from the SARS-CoV-2 pandemic.

The importance of antibodies, particularly neutralizing antibodies, has been known for decades. When examining the immune responses against a pathogen after a vaccination or infection it is easier to measure the levels of antigen-specific antibodies than the T-cell response, but it does not give the whole picture. The levels of neutralizing antibodies are harder to determine but give a better indication of the quality of the antibody response. The induction of long-lived antibody-secreting plasma cells is crucial for a persistent humoral immune response, which has been shown for example after vaccination with the vaccinia vaccine, where antibody levels have been shown to persist for decades. With the SARS-CoV-2 pandemic ravaging the world for the past years and the monumental effort in designing and releasing novel vaccines against the virus, much effort has been put into analysing the quantity, quality, and persistence of antibody responses.