New research on UK coronavirus variant worries scientists


The variant of the coronavirus that emerged in the UK now belongs to the world, and a growing body of evidence confirms the first suspicions of some scientists: it is a super spreader capable of supercharging the pandemic and beefing up the less transmissible strains of the virus in oblivion.
Now that the new variant has established a beachhead in the United States and more than 40 other countries, the race to contain it is on. This competition pits humans armed with vaccines, masks and hand sanitizer against a viral strain with a handful of genetic changes that have sparked fears since the time they were detected.

There’s good news: Researchers who have measured and modeled the powers of the British variant have found no reason to believe that it makes people sicker once it invades their bodies. It also doesn’t appear to reduce the time it takes for a newly infected person to be able to spread the virus – a development that could generate rapid waves of new patients.

And other new research strengthens the case that COVID-19 vaccines given in the United States and elsewhere should protect against the new variant.

But other results are more worrying. Using many different methods to track the British variant and compare it to its predecessors, two groups of researchers concluded that the rapid growth of the new strain across Britain cannot be taken for granted.

And as quickly as the new strain has spread to her homeland, she’s about to do even better here. Once it is established in the United States – a prospect that experts see as inevitable – to thwart it will require more stringent public health measures than those adopted so far, a more rapid deployment of vaccines and a significantly increased willingness to be vaccinated.

“We are losing the race with the coronavirus – it infects people a lot faster than we can get the vaccine in people’s arms, and it overcomes our social distancing,” University of Florida biologist Derek Cummings said, an expert in emerging pathogens. “Now there is this variant which will make this race even more difficult.”

“We are losing the race with the coronavirus. … Now there is this variation which will make this race even more difficult.

Derek Cummings, an emerging pathogen expert at the University of Florida

The genetic changes in the new variant appear to have increased its transmissibility by around 56%, according to the new research, although it could be as low as 40% and as high as 70%.

With this competitive advantage, it will quickly become the most common strain found in all the regions where it takes root. In doing so, coronavirus infections – and the resulting increase in illness, hospitalizations and deaths – will explode.

“Ultimately, it will be more difficult to control this new variant if it takes over,” said Ira Longini, an infectious disease modeler at the University of Florida who was not involved in any of the UK studies.

And he will take over, he added.

The superpower of the new variant, as evidenced by Britain, is its ability to pass through public health guardrails and spread easily. It had been spreading for at least a month and probably longer before it was detected by keen-eyed (and well-funded) geneticists in the UK.

The travel bans were arguably unnecessary for bottling it. The variant, known to scientists as B.1.1.7, has appeared in 47 countries so far, including countries as far away as Australia, Chile and Japan.

The port of Dover in England was closed in December after France issued a temporary travel ban from the UK to stop the spread of a new variant of the coronavirus.
(Kirsty Wigglesworth / Associated Press)

As recently as 2009, disease hunters saw strains of the flu virus with only a few new genetic modifications wipe out existing strains within a year, Longini said.

“I don’t see what would stop him,” he said. “It should be spread all over the planet.”

What does such improved transmissibility mean? Imagine a group of people without a mask, none of whom are immune to the SARS-CoV-2 virus. If a single person with a typical strain walks in and mingles for a few hours, two to three more people are likely to return home infected.

If the same party animal were infected with B.1.1.7, the virus would find 3.5 to 4.3 new victims during this same event.

This difference may seem small, but as new generations are infected, its effect will be magnified. In a month, a single person with the British variant could generate 150 new infections – almost quadruple the 39 cases that would result from a person with an older strain of the coronavirus.

In reality, the British variant would likely meet a little more resistance in the United States. At this point in the pandemic, up to 1 in 5 guests have already been infected and gained some immunity which could be of help. In addition, some social distancing is likely to be observed, the party could take place outside and many attendees are said to be wearing masks.

Under these circumstances, a person with a typical strain of SARS-CoV-2 would likely find only one person to infect; on a rare lucky night for the virus, two people would be left infected. At this rate, the pandemic is growing at a relatively majestic rate, and after a month, a total of three people have been infected.

B.1.1.7 changes this image. A carrier of the same group would transmit his infection to 1.5 to two other victims. After a month, the initial case results in 11 to 16 new infections.

In the competition between viral strains, this competitive advantage is important. The purpose of a virus is to find and invade new bodies. The variant that manages to capture more, and in turn infect even more bodies, will outrun its competitors and establish its dominance.

In no time, the more timid stumps are completely ousted from the landscape, and the brash newcomer is calling the pandemic shots.

For example, experts warn that the increased transmissibility of B.1.1.7 will increase the proportion of the population that must be vaccinated to achieve herd immunity and end the pandemic.

To deny a virus enough new victims to keep the pandemic alive and growing, you need to surround more of its carriers with non-infectable – in other words, vaccinated – people who will stand in its way and make transmission. more difficult. The better a virus infects new victims, the more uninfectable people in the population are needed to block its path to a new victim.

Even before the threat of B.1.1.7 was fully understood, U.S. health officials were increasing their estimates of the number of Americans who would need to be vaccinated to establish herd immunity here. Although their initial estimates were around 70% of the population, experts including Dr Anthony Fauci, the country’s leading infectious disease specialist, raised their target to 85%.

Yet in a survey conducted in early December, the Kaiser Family Foundation found that only 71% of Americans would definitely or likely take a COVID-19 vaccine. Other recent surveys reported that the proportion of consenting Americans was just over half.

In Britain, the increased contagiousness of the British strain has been demonstrated by two groups of researchers using several techniques.

The first group, an influential team of infectious disease modellers from Imperial College London, used genetic sequencing techniques that allowed them to time-stamp infections and track the progression of the virus in a population. They compared the growth of B.1.1.7 in three separate regions of England and found similar growth patterns in all of them.

For further confirmation, they looked at hundreds of positive coronavirus tests. In rudimentary genetic testing widely used to confirm infection, the British strain sets off a telltale signal, betraying the presence of changes of its own.

By this measurement, too, the location and growth rates of the new genetic variant – and its continued ability to sideline other strains – allowed researchers to estimate how more transmissible it is. And he told them that its rapid growth could not be explained by local conditions (such as a particularly vulnerable population of older people) or environmental circumstances (such as colder weather which forced people to spend more time in the city). interior) which favored the new variant over the existing one. viral strains.

Ambulances line up outside the Royal London Hospital as the new strain of coronavirus fuels a record rise in COVID-19.

(Dominic Lipinski / Associated Press)

The second group of researchers, from the London School of Hygiene and Tropical Medicine, used many of the same techniques. They adapted the outbreak data in mathematical models to show the similarity of the B.1.1.7 footprint in different regions and explore possible reasons for the consistency they observed.

They concluded that the rapid rise in infections in Britain must be fueled by one or more of the changes in the genetic code of the new variant, although they are not sure which made the difference.

It is an inference. But the experts said it was a good solution.

“If you gave me any evidence of these studies, I would say I don’t buy it entirely,” said UC Irvine biostatistician Vladimir Minin, who was not involved in either study. “But the authors provided a lot of evidence that even the most skeptical of us couldn’t dismiss. This is pretty solid proof that this really is a virus that spreads faster. ”

“This is pretty strong proof that this really is a faster spreading virus.

Vladimir Minin, biostatistician at UC Irvine

In a country that is already struggling to get people to wear masks, stay home and avoid gatherings, vaccines seem to be the only way out. And the arrival of B.1.1.7 argues more than ever to prioritize the elderly and those most at risk of becoming seriously ill or dying from infection, said Dr Marc Lipsitch, director of the Center for Communicable Disease Dynamics from Harvard. That way, even if Americans can’t stop the spread of a more difficult virus, vaccines can “neutralize” its impact, he said.

But first, says Cummings, you have to give them time to work. And that will require more draconian public health efforts if more deaths are to be avoided.

It’s a time similar to the early days of the pandemic, when Americans were asked to make sacrifices to “flatten the curve” to give hospitals time to stock up on ventilators, protective gear and healthcare workers. This time, the curve to be flattened is steeper.

Still, Cummings said, “We shouldn’t just give up and say this is a lost cause. Every week that we receive helps us. We have these public health tools and we can all do something to delay infections and give ourselves more time to get vaccines out.


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