Friday, September 20

Answers to your questions about coronavirus mutations

The emergence of potentially faster-spreading variants of the coronavirus has increased concern about the trajectory of the virus, just as the vaccines are distributed which many hope will end the pandemic .

The variant that caused the most alarm was first found in England, leading to new travel restrictions for travelers from the UK and, as of Monday, to a major new national blockade in that country. But it has already been detected in 30 countries, including the United States.

The first known case in the United States was identified on 29 December, in Colorado, on someone with no travel history. Another case was found the next day in San Diego. New York announced that its public health laboratory identified a case Monday, also in someone with no travel history.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases , told PBS Newshour last week that he suspected the variant was already here, but added that “it doesn’t seem to have any impact on virulence or what we call the virus mortality ”. It doesn’t make people worse. And it doesn’t seem to have any impact on the protective nature of the vaccines that we are currently using. ”

The United States now requires that people arriving here from the UK by plane present a negative result on a PCR or antigen test no more than 72 hours before departure.

Infectious disease experts point out that viruses always mutate. This virus, like many others, constantly acquires and loses genetic traits as it spreads.

“I would not be surprised if there are additional new strains in the population that have not yet been identified, ”says James Dickerson, PhD, Consumer Reports chief science officer.

Here’s what we know about the variants causing concern right now.

Why do viruses mutate? Viruses such as SARS-CoV-2, which cause COVID – 19 , they make imperfect copies of themselves as they are passed from person to person or animal to person, leading to constant mutations and new variants, says Peter Katona, MD, infectious disease specialist and clinical professor of medicine at UCLA David Geffen School of Medicine. These mutations do not usually give the virus any advantage. However, sometimes a mutation can make a virus more transmittable or change the severity of the disease caused by the virus .

How has the coronavirus mutated? The SARS-CoV-2 virus emerged for the first time in China and continued to mutate as it spread throughout the world. A variant that was probably more contagious emerged in Europe, Katona says. The infectivity of this variant helped it spread rapidly through Europe and the United States, where it became one of the most dominant strains.

The variant under investigation in the United Kingdom has a large number of mutations, according to the ECDC report, including changes in the protein S (spike protein) that the coronavirus uses when infecting cells. After comparing the number of coronavirus cases in the UK with predicted cases using computer models, scientists believe that this variant could be up to 56% more infectious than existing variants.

But while these models seem to indicate that the new variant is spreading faster than the Earlier strains of the virus, people traveling on vacation could also account for the increase in the number of cases. Scientists need more information before knowing if and to what degree this variant is more infectious, says Gregory Poland, MD, professor of medicine and infectious diseases and director of the Vaccine Research Group at the Mayo Clinic.

There is no data to indicate that this variant of the virus causes people to get sicker. But a more infectious variant would lead to more deaths and serious cases in the long term, as cases could grow exponentially, putting already hospital systems under increased pressure, Poland says.

Where are current mutations spreading? Cases of the variant that being investigated in the United Kingdom are found primarily in Kent, the London regions and south-east England, according to the ECDC. But this version has also been identified in Wales, Denmark, Belgium, the Netherlands, Australia, Canada and elsewhere, indicating that it has also spread internationally. The first known case in the United States was identified on Tuesday, in Colorado, in someone with no travel history.

Other countries, including the United Kingdom, perform more routine virus sequencing than the United States, which makes it difficult to know for sure if the variant is already here. (Sequencing is the type of analysis that scientists do to determine the variant of a virus that causes a particular case or outbreak.) Viruses have been sequenced into only 51,000 of the 17 million cases of COVID – 19 in the United States, According to the Centers for Disease Control and Prevention (CDC).

With this new variant now in the United States, public health officials are already stepping up their sequencing efforts, said the 30 December Dr. Gregory Armstrong, Director of the Office of Advanced Molecular Detection at the Centers for Disease Control and Prevention (CDC) , aiming to soon sequence 3, 000 viruses per week . That data should help provide a clearer picture of how widespread the variant is in the United States.

However, if this variant turns out to be more contagious, we should expect it to spread more say Katona and Poland.

Although the large number of mutations in this variant has raised doubts about its emergence, it is not the only variant of the virus that scientists are investigating. An evolutionarily distant variant with some similar mutations is spreading rapidly in South Africa, according to the ECDC, which could indicate that mutations like this are not uncommon.

Are children most affected by the new variant? Some data have indicated that younger children may be less contagious when infected with COVID – 19, although more research is needed on the subject. In general, children have been more likely to have asymptomatic or milder forms of the disease, according to the CDC, although they can contract, spread and be severely affected by it.

However , the rapidly increasing rates of infection among young people in the UK has many wondering whether the new strain may be more contagious to children, increasing the likelihood of transmission overall and making schools more risky.

“The confirmed infection rate in children is at its highest so far”, noted on Twitter Dr. Christophe Fraser, infectious disease epidemiologist at the Big Data Institute, Oxford and professor at the Nuffield Department of Medicine. On Monday, UK Prime Minister Boris Johnson announced that UK schools and colleges will close as the UK tries to control the current outbreak.

Some preliminary data indicates that the new variant can cause people to have a higher viral load, which essentially means they might have more virus particles to spread to others, Poland says at the Mayo Clinic. If that’s the case, it could be the cause of the seemingly high infectivity of this variant. If children had lower viral loads of previous variants of the coronavirus, but higher loads of it, that could explain why infection rates among children are increasing, he says, but adds that we need more research to confirm if that is. the case or not.

How can mutations affect the vaccine? Vaccines teach our immune system to respond to a virus by recognizing some key sign of it. Mutations that affect the parts of the virus that the immune system recognizes can help a virus to impair the efficacy of a vaccine .

The first vaccines that have been licensed in the United States for COVID- 19, manufactured by Moderna and a partnership of Pfizer and BioNTech, are addressed to one protein in particular, protein S, that the coronavirus uses to infect people. So mutations in that protein could make a vaccine less effective, Poland says.

But even if mutations in current variants of the virus have some impact on the efficacy of vaccines, vaccines can probably still be highly effective, he says.

Still, we may eventually need new vaccines that target other parts of the SARS-CoV virus- 2, wrote Poland in a comment for Vaccine magazine , of which he is the editor.

What should you do? Same advice on how stopping the spread of the virus is even more crucial if this mutation spreads faster. “The appropriate measure is precaution, following existing procedures for the use of masks, social distancing and minimizing the number of possible lines of exposure,” says Dickerson of CR.

The more The coronavirus spreads, the more it mutates, according to Poland and Katona.

“We are unnecessarily prolonging the duration and severity of this pandemic by not following a simple paradigm of hands, face and space” says Poland.

Editor’s note: This story has been updated to include new information as developments change. Originally posted on 22 December.

Consumer Reports is an independent, nonprofit organization that works side by side with consumers to create a fairer, safer, and healthier world. CR does not endorse products or services, and does not accept advertising. Copyright © 2021, Consumer Reports, Inc.

Consumer Reports has no financial relationship with the advertisers on this site. Consumer Reports is an independent, nonprofit organization that works with consumers to create a just, safe, and healthy world. CR does not endorse products or services and does not accept advertising. Copyright © 2021, Consumer Reports, Inc.