Variants seen in Brazil full of COVID


March 24, 2021-more contagious unrestricted spread coronavirus The different variants of Brazil seem to have created a more dangerous version of the virus that causes COVID-19.

A team of researchers from Fiocruz, a large public health research laboratory of the Brazilian Ministry of Health, documented these changes.Their findings were recently published In preprint on Virologic.org, Before peer review.

The study described 11 coronavirus sequences from five Brazilian states. Each viral receptor has obvious changes, making it one of the known variants. However, the N-terminal domain (NTD) of another important region of each virus also has other changes.

The change is the absence of important antibody binding sites. Many of these are key deletions of mutations that have emerged independently in other circulating variants and have been found in viral mutations in cancer patients during convalescence, indicating that it brings important advantages to the virus.

Since the beginning Pandemic, Scientists predict that the virus will mutate or change. The virus may also lose or gain part of its genetic code. There is a term in molecular biology: Indel, which means insertion or deletion. Read more about coronavirus variants here.

These insertions or deletions are more sudden changes than point mutations. When they appear in the spike protein of the virus, they can modify the shape of the coronavirus so that it can escape the grasp of the “key” antibody suitable for these binding sites.

Felipe Naveca, MD, vice president of research and innovation at Fiocruz Amazonia, said: “This NTD region produces many antibodies. Therefore, these mutations are likely to make the virus more resistant to neutralization.”

Modeling by Naveca and his team suggests that the deletion will limit the ability of antibodies to capture these viruses and prevent them from infecting us.

Naveca also said that these variants with indels are still uncommon. They were discovered early, and scientists believe that they have not yet spread widely.

The researchers said: “But this kind of testing is just a warning, we need to monitor their occurrence. That’s why genome surveillance is needed.”

Need to “close replication”

Due to mutation and political inaction, Brazil is in the midst of another wave of devastating COVID-19 infections.The hospital’s beds and other key supplies have been used up, such as Ventilator And oxygen, Brazilian President Jair Bolsonaro refused to require citizens to wear masks and rejected the idea of ​​imposing blockade measures, saying the cost to the country’s economy was too high.

Researchers who were not involved in the study said these findings should make the rest of the world vigilant.

John Mellors, director of the Department of Infectious Diseases at the University of Pittsburgh School of Medicine, said the discovery was “not surprising, but worrying.”

Mellors and his colleagues are part of a team of researchers who recorded the same changes in cancer patients who had struggled with the virus for more than 2 months.

Over time, genome sequencing showed that the patient is undergoing recovery treatment plasma And antiviral drugs Redesivir In order to enhance his immune response, he is the host of at least six different SARS-CoV-2 variants. This variant has many mutations carried by variants that appeared in the UK, South Africa, and Brazil.

The deletion of the N-terminal domain recorded in the new preprint has also been detected elsewhere in the world.

One Separate study, Published in the magazine earlier this month science, It was found that other deletions also hindered the antibody.Coping with infection or vaccine, Our body forms the entire y-shaped antibody band, and each y-shaped antibody is designed to catch the virus in a slightly different position. Therefore, the loss of one of these antibody docking sites on the virus itself does not necessarily cause an alarm. However, the more the shape of the coronavirus changes and changes, the more our immune defense loses its collective momentum. Eventually, this change causes the virus to re-infect or destroy the protection of the virus. vaccine.

Other researchers who were not involved in the study said that although the results of the study are interesting and noteworthy, it is still too early to determine the meaning of this particular combination of mutations.

“I am sure that there will be follow-up documents describing these documents as deaths, and like these documents, explain the exact impact of each document, and I am sure that it may be right in front of you, Pavitra, lecturer in the Department of Laboratory Medicine at the University of Washington in Seattle. Dr. Roychoudhury said.

immediately, according to CDC tracking variants did not result in a complete failure of tests, vaccines or treatments of the virus variants.

Mellors said: “The biggest action we all need to take is to vaccinate as widely as possible to prevent the virus from replicating.” “Without replication, there is no development. Therefore, if we turn off replication and spread, we will be fine. Yes, and on a global scale, shutting it down is a huge and huge task.”

Lack of public health measures

The variables that affect the evolution of the virus are the number of infections and the time of infection. Scientists agree that in order to slow down the evolution of the virus, it is essential to vaccinate quickly and prevent people from spreading. This has not happened in Brazil yet.

Study author Tiago Gräf, also a Fiocruz researcher, said: “This is very important to ensure the effectiveness of future vaccines. They are not designed to deal with this number of mutations.”

Graf said: “We defend the use of vaccines, and we believe they will continue to protect humans from serious diseases. However, this virus is so different from the original virus that new tests are needed to understand its effectiveness. Sex.”

Graf said: “We are showing new variants and their dangers. But the public administration is ignoring our warnings. What we see today is the result of this consequence.”

WebMD Health News

source

John Mellors, MD, Director of Infectious Diseases, University of Pittsburgh School of Medicine

Dr. Pavitra Roychoudhury, Lecturer, Department of Laboratory Medicine, University of Washington, Seattle

Virologic.org. Released on March 18, 2021.


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