PT  - JOURNAL ARTICLE
AU  - Fabian Schmidt
AU  - Yiska Weisblum
AU  - Magdalena Rutkowska
AU  - Daniel Poston
AU  - Justin Da Silva
AU  - Fengwen Zhang
AU  - Eva Bednarski
AU  - Alice Cho
AU  - Dennis J. Schaefer-Babajew
AU  - Christian Gaebler
AU  - Marina Caskey
AU  - Michel C. Nussenzweig
AU  - Theodora Hatziioannou
AU  - Paul D. Bieniasz
TI  - High genetic barrier to escape from human polyclonal SARS-CoV-2 neutralizing antibodies
AID  - 10.1101/2021.08.06.455491
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.08.06.455491
4099  - http://biorxiv.org/content/early/2021/08/08/2021.08.06.455491.short
4100  - http://biorxiv.org/content/early/2021/08/08/2021.08.06.455491.full
AB  - The number and variability of the neutralizing epitopes targeted by polyclonal antibodies in SARS-CoV-2 convalescent and vaccinated individuals are key determinants of neutralization breadth and, consequently, the genetic barrier to viral escape. Using chimeric viruses and antibody-selected viral mutants, we show that multiple neutralizing epitopes, within and outside the viral receptor binding domain (RBD), are variably targeted by polyclonal plasma antibodies and coincide with sequences that are enriched for diversity in natural SARS-CoV-2 populations. By combining plasma-selected spike substitutions, we generated synthetic ‘polymutant’ spike proteins that resisted polyclonal antibody neutralization to a similar degree as currently circulating variants of concern (VOC). Importantly, by aggregating VOC-associated and plasma-selected spike substitutions into a single polymutant spike protein, we show that 20 naturally occurring mutations in SARS-CoV-2 spike are sufficient to confer near-complete resistance to the polyclonal neutralizing antibodies generated by convalescents and mRNA vaccine recipients. Strikingly however, plasma from individuals who had been infected and subsequently received mRNA vaccination, neutralized this highly resistant SARS-CoV-2 polymutant, and also neutralized diverse sarbecoviruses. Thus, optimally elicited human polyclonal antibodies against SARS-CoV-2 should be resilient to substantial future SARS-CoV-2 variation and may confer protection against future sarbecovirus pandemics.Competing Interest StatementPDB has received consulting fees from Pfizer Inc relating to mRNA vaccines