Nature: antibodies have been identified that effectively fight the omicron strain of coronavirus
Photo: Thilo Schmuelgen / Reuters
An international team of scientists has identified antibodies that neutralize the omicron variant and other strains of the coronavirus. These antibodies target those regions of the S-protein that remain practically unchanged during the evolution of the virus. This is reported in an article published in the journal Nature.
The Omicron variant has 37 mutations in the S-protein of the coronavirus, which plays a key role in infecting human cells. In a new study, the researchers tried to figure out how the entire set of mutations affects the ability of SARS-CoV-2 to effectively bind to cells and evade neutralizing antibodies that target specific regions of the S-protein. To do this, they created a weakened virus that is incapable of reproduction (pseudovirus), which has S-proteins on the surface of the envelope, characteristic of the early strains of SARS-CoV-2 and the omicron variant.
It turned out that the S-protein “omicron” binds to the cellular receptor ACE2 2.4 times better than the earliest variants of coronavirus “spike” proteins. The scientists also confirmed that antibodies from people who were infected with earlier strains and from those who received one of the six most commonly used vaccines have a reduced ability to block infection.
Antibodies in people who had previously been infected and in those who received Sputnik V, Sinopharm vaccines, or a single dose of Johnson & Johnson had little or no ability to block the entry of the omicron variant into cells. The antibodies of people who received two doses of Moderna, Pfizer / BioNTech and AstraZeneca vaccines retained some neutralizing activity, although it decreased 20-40 times. In people who underwent revaccination with the third dose of RNA vaccines, the activity decreased fourfold.
The results of testing a large panel of antibodies showed that there are four large classes of antibodies that retained a high ability to neutralize the omicron. Members of each class target one of four S-protein regions that are present not only in SARS-CoV-2 strains, but also in the related group of coronaviruses. The discovery will help develop new vaccines and drugs to treat COVID-19.
