SARS-CoV-2 breakthrough infections elicit potent, broad, and durable neutralizing antibody responses

Cell. 2022 Mar 3;185(5):872-880.e3. doi: 10.1016/j.cell.2022.01.011. Epub 2022 Jan 20.

Abstract

Although infections among vaccinated individuals lead to milder COVID-19 symptoms relative to those in unvaccinated subjects, the specificity and durability of antibody responses elicited by breakthrough cases remain unknown. Here, we demonstrate that breakthrough infections induce serum-binding and -neutralizing antibody responses that are markedly more potent, durable, and resilient to spike mutations observed in variants than those in subjects who received only 2 doses of vaccine. However, we show that breakthrough cases, subjects who were vaccinated after infection, and individuals vaccinated three times have serum-neutralizing activity of comparable magnitude and breadth, indicating that an increased number of exposures to SARS-CoV-2 antigen(s) enhance the quality of antibody responses. Neutralization of SARS-CoV was moderate, however, underscoring the importance of developing vaccines eliciting broad sarbecovirus immunity for pandemic preparedness.

Keywords: COVID-19; Delta variant; SARS-CoV-2; antibodies; breakthrough infection; neutralization; vaccine.