Broadly Neutralizing COVID-19 Antibodies Identified

An international team of scientists led by researchers at the University of Washington has identified antibodies that neutralize omicron and other SARS-CoV-2 variants. The findings were published in Nature.

“The main questions we were trying to answer were: how has this constellation of mutations in the spike protein of the omicron variant affected its ability to bind to cells and to evade the immune system’s antibody responses,” investigator David Veesler said. To assess the effect of these mutations, the researchers created pseudoviruses that had spike proteins with the omicron mutations and those found on the earliest variants identified in the pandemic.

They found the omicron variant spike protein was able to bind 2.4 times better than the spike protein found in the virus isolated at the very beginning of the pandemic. “That’s not a huge increase,” Veesler noted, “but in the SARS outbreak in 2002-2003, mutations in the spike protein that increased affinity were associated with higher transmissibility and infectivity.” They also discovered that antibodies from people who had been infected by earlier strains and from those who had received one of the six most-used vaccines currently available all had reduced ability to block infection. Antibodies from people who had been infected, recovered, and then had two doses of the vaccine also had reduced activity, but the reduction was less, about fivefold, clearly demonstrating that vaccination after infection is useful.

The finding that antibodies are able to neutralize via recognition of conserved areas in so many different variants of the virus suggests that designing vaccines and antibody treatments that target these regions could be effective against a broad spectrum of variants that emerge through mutation, Veesler concluded.