Science you need to understand

(Conversation) The SARS-CoV-2 virus mutates rapidly. These more contagious variants of SARS-CoV-2 are currently present in the United States, United Kingdom, South Africa, and other countries, and many wonder if current vaccines protect recipients from the virus. This is a concern because I am thinking. In addition, there are many questions about whether we can be ahead of future variants of SARS-CoV-2 that will definitely occur.

In my laboratory, I am studying the molecular structure of RNA viruses that cause COVID-19 and how they replicate and multiply in the host. SARS-CoV-2 continues to evolve as the virus infects more people and the pandemic spreads. This evolutionary process is constant and allows the virus to sample its environment and select changes to grow more efficiently. Therefore, it is important to monitor the virus for new mutations that can make it more deadly, more contagious, or both.

RNA virus evolves rapidly

The genetic material of all viruses is encoded in either DNA or RNA. One of the interesting features of RNA viruses is that they change much faster than DNA viruses. Every time they make a copy of a gene, they make one or some mistakes. This is expected to occur multiple times in individuals infected with COVID-19.

Some people may think that it is bad to make a mistake in genetic information. After all, that is the basis of human genetic disease. In the case of RNA viruses, a single change in their genome can result in a “dead” state. If you’re making thousands of copies inside an infected human cell and some are no longer useful, it’s not that bad.

However, some genomes may pick up changes that are beneficial to the survival of the virus. Perhaps this change allows the virus to evade antibodies (proteins that the immune system produces to catch the virus) or antiviral drugs. Another beneficial change may allow the virus to infect different types of cells or even animals of different species. This may be the pathway that allowed SARS-CoV-2 to move from bats to humans.

All changes that give the offspring of the virus a competitive growth advantage are prioritized, “selected” and begin to grow larger than the original parent virus. SARS-CoV-2 is currently demonstrating this function, and new variants with enhanced growth characteristics are emerging. Understanding the nature of these alterations in the genome provides scientists with guidance for developing countermeasures. This is a classic cat and mouse scenario.

Infected patients have hundreds of millions of individual viral particles. Detecting one virus at a time in this patient results in a mixture of different mutations and mutations. It’s a question of which ones have growth benefits, that is, which ones can evolve because they are better than the original virus. They will be successful during the pandemic.

Is one of the mutations detected of particular concern?

A single variant or modification of the virus is probably less of an issue. A single change in peplomer, a region of the virus that attaches to human cells, will probably not pose a major threat as the medical community deploys vaccines.

Current vaccines induce the immune system to produce antibodies that recognize and target viral spelomers. It is essential for invasion of human cells. Scientists have observed the accumulation of multiple changes in peplomer proteins in South African variants.

Preliminary, unpublished studies show that these changes, for example, allow SARS-CoV-2 to adhere more tightly to the ACE2 receptor and enter human cells more efficiently. These changes make the virus more susceptible to cell infection and may be more infectious. Multiple changes in peaplomers can prevent the vaccine from producing a strong immune response against these new variant viruses. It’s a double pain: less effective vaccines and more powerful viruses.

For now, the general public does not have to worry about current vaccines. Leading vaccine manufacturers are monitoring how well vaccines control these new mutants and are ready to fine-tune their vaccine designs to ensure protection from these new mutants. I will. For example, Moderna states that the second or booster infusion will be coordinated to more closely match the sequence of South African variants. As more people get vaccinated, we need to wait for the infection rate to decrease.

Why lower the transmission key?

A lower infection rate means less infection. Less virus replication reduces the chances of the virus evolving in humans. Less chance of mutation slows the evolution of the virus and reduces the risk of new variants.

The medical community needs to be very powerful and immunize and protect as many people as possible. Otherwise, the virus will continue to grow in many people and spawn new variants.

Differences between new variants

B.1.1.7. The British variant known as ACE2 appears to bind more strongly to a protein receptor on the surface of human cells called ACE2.

I don’t think there was clear evidence that these viruses were more pathogenic and more deadly. However, they can be sent faster or more efficiently. In other words, more people will be infected and more people will be hospitalized.

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The South African variant, known as 501.V2, has multiple mutations in the gene encoding the peplomer. These mutations help the virus evade antibody reactions.

Antibodies have exquisite accuracy with respect to the target, and slight changes in the shape of the target, such as this variant, which virologists call escape mutants, cause the antibody to lose its protective power and become unable to bind tightly. ..

Why do you need to monitor mutations?

I would like to make sure that the diagnostic test detects all the viruses. If the genetic material of the virus is mutated, antibody or PCR tests may not be able to detect the virus efficiently or at all.

To ensure that the vaccine is effective, researchers need to know if the virus is evolving and escaping the antibodies evoked by the vaccine.

Another reason why monitoring new variants is important is that if the virus mutates and the immune system cannot recognize it and shut it down, infected people can become infected again.

The best way to look for new mutants in the population is to perform a random sequence of SARS-CoV-2 virus from patient samples across diverse genetic backgrounds and geographic locations.

The more sequence data a researcher collects, the better the vaccine developer will be able to respond to major changes in the viral population. Many research centers in the United States and around the world are enhancing their sequencing capabilities to achieve this.

This article has been republished from Conversation under a Creative Commons license. Read the original article here: https://theconversation.com/coronavirus-variants-viral-mutation-and-covid-19-vaccines-the-science-you-need-to-understand-153771..