Scientists have identified a new antibody that may neutralize Omicron

Scientists have identified a new antibody that may neutralize Omicron

Scientists have identified a new type of antibody that is expected to neutralize the mutant strain of the new coronavirus Omicron!

Recently, in a research brief titled “Broadly neutralizing antibodies overcome SARS-CoV-2 Omicron antigenic shift” published in the international journal Nature , scientists from Washington University School of Medicine and other institutions have identified the energy Antibodies that can effectively neutralize the mutant strain of the new coronavirus Omicron and other SARS-CoV-2 mutants.

These antibodies may target the spike protein region of the virus, which will basically remain unchanged as the virus mutates. 

Researcher David Veesler said that by identifying the targets of these broad-spectrum neutralizing antibodies on the spike protein, we may be able to design vaccines and antibody therapies to effectively defend against Omicron mutant strains and possible future occurrences.

Other mutant strains; the findings in this article tell us that by focusing on antibodies against highly conserved sites on the spike protein, it may be possible in the future to develop a new method to overcome the continued evolution of the virus.

The Omicron mutant strain has 37 mutation sites on the spike protein, which can use these mutation sites to lock and invade host cells.

This mutation is an abnormally high number of mutations; scientists believe that this change It may partly explain why the mutant strain can spread so quickly, and infect people who have been vaccinated, and reinfect people who have not been previously infected.

The main question that researchers are trying to answer today is how the combination of these mutations in the spike protein of the Omicron mutant strain affects its ability to bind to cells and evade the immune system’s antibody response.

Researcher Veesler and colleagues speculate that the large number of mutations produced by the Omicron mutant strain may accumulate in a long-term infection of a patient with a weakened immune system, or the virus may jump from human to animal species and then return. Into the human body.

In order to assess the impact of these mutations, the researchers designed a loss-of-function and unable to replicate virus, the pseudovirus, to produce spike proteins on its surface, just like coronaviruses; then they A pseudovirus carrying the Omicron mutation on the spike protein was created, as well as the mutation on the mutant strain that was first discovered in the pandemic.

The researchers first observed how different versions of spike proteins bind to cell surface proteins and the extent to which they bind. Viruses can use spike proteins to lock and invade host cells.

This protein is called angiotensin converting enzyme- 2 (ACE-2) receptor. Researchers have found that compared with viruses isolated early in the COVID-19 pandemic, the spike protein of the Omicron mutant strain is 2.4 times more capable of binding to host cells. This may not be a huge increase.

The researchers pointed out that in the SARS epidemic that broke out in 2002-2003, the mutation of the spike protein that can increase the affinity may be related to the higher transmission and infectivity of the virus.

In addition, the Omicron mutant strain can be more effective Binding to the ACE2 receptor in mouse cells indicates that the Omicron mutant strain may be able to spread between humans and other mammals.

The researchers then analyzed the level of antibodies against the early isolates of the virus against the Omicron mutant strain.

They used the antibodies of patients who had previously been infected with the early version of the virus or individuals who had been vaccinated against the early version of the virus to make the correlation.

As a result, it was found that antibodies from individuals who had been infected by the early virus or individuals who had been vaccinated with one of the six most commonly used vaccines could reduce the ability to block the infection of the Omicron mutant strain.

The antibodies produced by patients who have been infected before, and those who have been vaccinated with China Pharmaceutical Group’s COVID-19 vaccine and a single dose of Johnson & Johnson vaccine can hardly or can not block/neutralize the cells of the Omicron mutant strain from entering the host’s body;

The antibodies of individuals who have received two doses of Moderna, Pfizer/BioNTech and AstraZeneca vaccines may retain part of their neutralizing activity, although their activity is reduced by 20-40 times, which is more effective than resisting other variants of the new coronavirus.

The antibody activity of individuals who have been infected, recovered and have been vaccinated with two doses may have decreased, but the decrease is small, about 5 times, which clearly reveals the protective effect of vaccination after infection.

The researchers said that after receiving the third dose of Moderna and Pfizer/BioNTech’s mRNA vaccine booster, the neutralizing activity of the antibodies produced by the kidney dialysis patients only decreased by 4 times, which shows that the third dose of vaccine It is very useful for resisting Omicron mutant strains.

Except for an antibody therapy that is currently authorized or approved for exposure to the virus, all other antibody therapies currently have no activity against the Omicron mutant strain in laboratory tests or have significantly decreased activity; and the study found , Sotrovimab antibody may be an exception, and its neutralizing activity is reduced by 2-3 times.

Image source: https://www.nature.com/articles/d41586-021-03825-4

But when the researchers tested a larger group of antibodies against an earlier version of the virus, the researchers found that there are four types of antibodies that retain the ability to neutralize the Omicron mutant strain.

Antibodies in these categories can Targeting One of the specific regions of the four-clock spike protein of the Omicron mutant strain, and these regions not only exist in the SARS-CoV-2 strain, but also in a group of related coronaviruses (sarbecoviruses) .

These sites on the protein can continue to exist because they play a very important role. If they are mutated, the protein will lose the function of the response. Such regions are considered to be functionally conserved regions.

In summary, the results of this article show that among so many virus mutant strains, researchers have discovered antibodies that can neutralize mutant strains by identifying conserved regions.

This may indicate that new vaccines or antibody therapies can be designed to target.

The conserved region of the spike protein of the mutant strain may be able to effectively resist the broad-spectrum COVID-19 mutant strain that can emerge through mutation .

Reference：

Elisabetta Cameroni,John E. Bowen,Laura E. Rosen, et al. Broadly neutralizing antibodies overcome SARS-CoV-2 Omicron antigenic shift, Nature (2021). DOI: 10.1038/d41586-021-03825-4

Scientists have identified a new antibody that may neutralize Omicron

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