Scientists have identified antibodies that neutralize Omicron and other variants of Coronavirus by targeting areas that basically do not change as viruses mutate.
This research, published in the journal Nature, can help design vaccines and antibody treatments that will be effective against not only Omicron but other variants that might arise in the future.
“This finding tells us that by focusing on antibodies targeting these sites that are very hampered in the protein surge, there are ways to overcome the continuous evolution of the virus,” said David Veesler, an Associate Professor at the University of Washington School of Medicine at the University United States of America.
The omicron variant has a number of 37 tremendous mutations in protein surges, which are used by viruses to enter and infect human cells.
It is estimated that this change explains in part why variants have spread so fast, to infect people who have been vaccinated and infect those who have previously been infected.
“The main question we are trying to answer is: How the constellation of this mutation in the protein surge by the omicron variant affects its ability to bind cells and to avoid the antibody response of the immune system,” Veesler said.
To assess the effects of these mutations, the researchers engineered viruses were disabled and non-coated, called pseudovirus, to produce a surge protein on its surface, as conducted by Coronavirus.
They then created pseudovirus which had protein surge with Omicron mutations and found in the earliest variants identified in pandemic.
The researchers first saw to see how well different versions of protein surges can bind proteins on the cell surface, which the virus used to lock and enter the cell. This protein is called an Angiotensin Conversion Enzyme-2 receptor (Ace2).
They find the omicron spike protein variant can bind 2.4 times better than a surge protein found on the isolated virus at the beginning of the pandemic.
“It was not a large increase but in the SAR outbreak in 2002-2003, mutations in the protein surge increased affinity were associated with higher transmission and infectivity,” Record Veesler.
They also found that the omicron version can bind ace2 mouse receptors efficiently, suggest Omicron may be able to “ping-pong” between humans and other mammals. The researchers then saw how well the antibodies of the previous virus isolates were protected against the Omicron variant.
They did this by using antibodies from patients who had previously been infected with the previous virus version, vaccinated from previous viral strains, or had been infected and then vaccinated.
The team found that antibodies from people who had been infected by previous strains and from those who had received one of the six most widely used vaccines currently available all have reduced infection capabilities.
Antibodies from people who have been infected, recover, and then have two doses of vaccines also have reduced activity, but the reduction is lacking, about five times, clearly indicating that vaccination after a useful infection. Antibodies from people, in this case a group of kidney dialysis patients, who have received a booster with the third dose of the MRNA vaccine produced by Moderna and Pfizer only shows a 4-fold reduction in neutralization activities.
“This shows that the third dose really, very helpful against Omicron,” Veesler said. All but one antibody treatment is currently authorized or approved for use with patients exposed to viruses, do not have or have reduced activity against omicrons in the laboratory.