November 29, 2021

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South Africa COVID-19 mutant virus is much more serious

South Africa COVID-19 mutant virus is much more serious

 

South Africa COVID-19 mutant virus is much more serious. How powerful is the South African COVID-19 mutant virus? Will the vaccine we are going to get still useful? This undoubtedly sounded the alarm: the virus mutation situation is grim! So, will the “extreme weapon” vaccine we rely on face such a cunning virus, will the effect be greatly compromised?

Since the outbreak of the n COVID-19 virus, the n COVID-19 virus has been constantly mutating, and scientists are also constantly discovering COVID-19 mutant strains. Fortunately, these mutant strains only improve the transmission ability, but do not seem to increase the pathogenicity, and there is no vaccine. The effect has an impact.

However, on December 18, 2020, South Africa detected a new coronavirus variant—501Y.V2 variant, which contains three key mutations: K417N, E484K, and N501Y. The South African mutant has now spread to 20 countries. China has also reported imported cases of this mutant strain.

More unfortunately, on January 19, 2021, the Rockefeller University, California Institute of Technology, National Institutes of Health and other research teams collaborated to publish the latest research: the protective ability of the n COVID-19 vaccine against the South African mutant strain 501Y.V2 variant There may be a decline. Among the neutralizing antibodies isolated from volunteers vaccinated with mRNA vaccines, 26% of the neutralizing antibodies (22) have a more than 5-fold decrease in the neutralizing activity of the mutant strain.

This undoubtedly sounded the alarm: the virus mutation situation is grim! So, will the “extreme weapon” vaccine we rely on face such a cunning virus, will the effect be greatly compromised?

 

Why is the South African strain terrifying?

South Africa COVID-19 mutant virus is much more serious

The horror of the South African strain starts with the structure of the new coronavirus. The genetic material of the new coronavirus is located inside the virus and forms the core of the virus. The protein surrounds the genetic material to form a capsid, also called a shell.

The new coronavirus has an envelope structure with three proteins:

  • Spike Protein (S, Spike Protein),
  • Envelope Protein (E, Envelope Protein)
  • Membrane glycoprotein (M, Membrane Protein).

Among them, S protein plays a key role in recognizing and binding host cell surface receptors and mediating the fusion of virus envelope and cell membrane.

One of the vaccine protection strategies is to target the S protein, induce the human B cells to produce neutralizing antibodies, prevent the S protein from binding to the host cell surface receptors, and effectively protect the host from the invasion of the new coronavirus.

Here is a dangerous situation: if the virus S protein is mutated, it means that the neutralizing antibodies produced by the previous vaccine may be invalid. This is also the study of the US team found that the neutralizing activity of some neutralizing antibodies against the mutant strain is greatly reduced. The core reason.

The South African mutant strain involves mutations at three sites: K417N, E484K, and N501Y are three key mutations. Among them, E484K affects the S protein, which will challenge the existing vaccine program. At the same time, the S protein appears A mutation site that has received much attention may allow viruses to invade cells more easily.

Therefore, another distinguishing feature of the mutant strain in South Africa is that it spreads very quickly: it has become the main strain in South Africa in just a few weeks after its discovery. This means that the transmission ability of the strain’s S protein after mutation is indeed greatly improved!

 

What is the impact of the South African strain?

The three research teams of Rockefeller University, California Institute of Technology, and National Institutes of Health are the world’s top virology, immunology, and structural biology laboratories. The three teams work together to crack the South African strain for vaccines. The impact of prevention and control strategies.

The idea of ​​the study is to extract the serum of the vaccinated mRNA vaccine to study whether the neutralizing activity of the vaccinated serum against the South African strain has changed.

A total of 86 neutralizing antibodies were isolated from the sera of vaccinators, but unfortunately, 26% (22/86) of the neutralizing antibodies isolated from vaccinators were more than 5 times less effective against the South African strain.

There are two points worth noting here:

  • First of all, not all neutralizing antibodies are greatly compromised. Only 26% of neutralizing antibodies are more than 5 times less effective. This is a blessing in misfortune, which means that the neutralizing activity of mRNA vaccination against the South African strain may decrease, but the decrease is limited.
  • Secondly, the target population is those vaccinated with mRNA vaccines, and China’s mainstream COVID-19 vaccine program is made by inactivation technology. Whether the South African strain will affect the inactivated vaccines, this article does not give an explanation.

However, Yang Xiaoming, chairman of Sinopharm Group China Biotech, said in an interview with CCTV on January 15 that researchers have conducted experiments on various mutant strains from different regions to immunize volunteers in phase I and II clinical trials. The serum has also done a comprehensive experiment.

 

There are clear data that the vaccine has a preventive effect on various variants. After being immunized with the inactivated vaccine, it has a neutralizing effect on different variants including British mutant strains and about eight or nine strains isolated in the past globally.

Therefore, China’s new coronavirus inactivated vaccine is broad-spectrum protection, and has good cross-neutralization against strains from different regions of the world.

Although the South African strain has a key mutation at the core site E484K, which greatly reduces the effectiveness of the partially neutralizing antibody produced by the mRNA vaccine, the impact is limited.

Finally, the researchers of the US team suggested that: vaccination is still effective against South African strains, so expanding vaccination is essential.

 

In case the virus mutates seriously, Can vaccines have prevention and control strategies?

Although the South African virus has undergone mutations at three key sites, the effectiveness of some neutralizing antibodies is greatly reduced, and the impact is limited. If the new coronavirus continues to mutate, if it can completely break away from the effectiveness of the neutralizing antibody produced by the existing vaccine, then do we have appropriate countermeasures?

In fact, virus mutation is really very common in nature. Don’t panic when you mention “mutation”. To give a simple example: the familiar influenza virus is the “chameleon” that is constantly changing.

The flu virus that prevailed this year may be completely different from last year, but this does not hinder the effect of flu vaccines. We can make trivalent or even quadrivalent flu vaccines based on the several strains that are prevailing at the moment. Protective effects.

Therefore, for the mutation of the new coronavirus, we can completely adopt the same strategy as the flu vaccine to make a multivalent vaccine. It is really the so-called “the enemy changes and we change, and the enemy wins.”

What I have to mention here is that the flu vaccine is an inactivated vaccine program, while the mainstream new coronavirus vaccine program in China is made using an inactivated process. This seems to be of our own will. We started to design the new coronavirus vaccine at the earliest. , We have made sufficient preparations for the worst possible outcome!

Even if there is a divergence in the battle for vaccine routes in the future, we are still invincible. We not only have our own inactivated vaccines, but at the same time, Fosun Pharma has cooperated with Germany’s BioNTech and entered the mRNA track. This is also the American Pfizer. The same paragraph as the mRNA vaccine!

 

(source:internet, reference only)


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