The journal Nature published the results of a study, the authors of which, a group of American and Swiss biochemists, studied mutations in the spike protein of the omicron strain and found out which antibodies are capable of neutralizing it, phys.org reports.
Omicron has 37 mutations in a spike protein that is used to enter cells. Scientists believe this unusually large number of mutations is one of the reasons for the extremely rapid spread of the new strain and its ability to infect vaccinated and recovered patients.
The researchers created "disabled", non-replicating strains of the pseudovirus - some of them had spike proteins with "omicron" mutations, others - of early variants. It turned out that the omicron spike protein is able to bind to cells 2.4 times more efficiently. It also turned out that it can attach to the ACE2 receptors of rodents - that is, it is able to "jump" between humans and other mammals.
Antibodies obtained from the Sputnik V vaccines, Sinopharm, Johnson & Johnson, had practically zero ability to block or neutralize the penetration of the omicron into cells. The antibodies of those who received two doses of Moderna vaccines, Pfizer / BioNTech and AstraZeneca, retained some neutralizing activity, although they decreased 20-40 times.
Antibodies from people who were infected, recovered, and then received two doses of the vaccine also had reduced activity, but the decline was less than a factor of five. This proves that post-exposure vaccination is beneficial.
The researchers also identified four classes of antibodies that retained the ability to neutralize the omicron. Each of them targets one of four specific regions of the spike protein, which remain unchanged, because if they mutated, the protein would lose its function. The development of vaccines and antibody therapies targeting these “conserved” areas could work not only against the omicron, but also against future strains. There is a chance that this will help and stop the continuous evolution of the virus.