An underlying motivation for the current development of vaccines against the coronavirus SARS-CoV-2 is the premise that neutralizing antibodies will provide lasting protection from infection, drawn in part from experiences with other anti-viral vaccines. This desire to elicit neutralizing antibodies via a vaccine stems from the idea that antibodies should prevent infection if they block entry of the virus into the cell. One common benchmark for measuring vaccine efficiency is eliciting neutralizing antibody levels similar to those elicited by natural infection, on the basis of the assumption that infection induces responses that protect against reinfection. In the case of SARS-CoV-2, recent reports of reinfection, as indicated by viral sequence differences, clinical data and data on potential exposure, have raised critical questions about whether and how well a first infection protects against reinfection.
