New strain of coronavirus splits scientists as UK and others act to stop spread

Transmissibility – how easily the virus spreads from one person to another – and the severity of the disease it causes are both important measures of the potential threat. And scientists say there is still a lot they don’t know.

Viruses naturally mutate, especially RNA viruses such as the new coronavirus. Many variants of the novel coronavirus have surfaced since it raced around the world.

Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases, said he expects the variant to circulate in the US if it is not already in the country, but said he did not believe it was a factor in the US . the current increase in infections in the US.

He said he does not believe the US should stop flights from the UK, but that “I think you would consider the possibility of requiring people boarding a plane and flying from England to be in the last 48 hours. tested at 72 hours. “

Dozens of countries around the world have moved to curb travel from the UK, the US has not. New York has asked airlines to require all UK passengers to pass a negative Covid-19 test before boarding flights to the state.

Health experts and pharmaceutical industry officials say they expect newly authorized vaccines, which induce virus-inhibiting responses that target different areas on the pathogen’s surface, will protect against the new variant.

Ugur Sahin, the CEO of BioNTech SE,

that partnered with Pfizer Inc. on a vaccine, said Tuesday that he thought the shot would work against the new version of the virus, but that if it is indeed more transmissible, it could raise the threshold needed to protect the community.

“If the virus becomes more efficient at infecting humans, we may need an even higher vaccination coverage to ensure normal life can continue without interruption,” he said.

Still, David Dowdy, an epidemiologist at the Johns Hopkins School of Public Health, said higher vaccination coverage would not be necessary, even if the variant turns out to be more transmissible, as long as enough people are vaccinated.

“If we can successfully vaccinate a large portion of the population, I don’t think the additional transmissibility of this variant will be enough to overcome that very strong effect,” he said.

The UK government has been alerted in recent days to data indicating that the new variant is spreading between 50% and 70% faster than other strains of the virus.

British scientists looked at how often the new variant was detected, whether changes in replication might make it more transferable, and what data showed about the correlation between the increase in the number of cases and the increase in the detection of the new variant.

“All three pieces of evidence all point in the same direction that this virus is a new variant that is slightly more transmissible than the existing virus,” said Peter Horby, a professor at the University of Oxford who chairs the Nervtag panel. , which advises the UK government on new and emerging threats from the respiratory virus.

But he added that more research was needed to find out how much more transferable it is and the biology behind it. “We still don’t understand the exact biological mechanisms of this, there is still a lot of uncertainty about exactly how it happens, the exact magnitude of the extra transferability.”

British scientists have been actively tracking mutations in the virus and sequenced the genomes of 160,000 samples of novel coronavirus, or 10% of all Covid-19 cases in the country. All told, British researchers say their work accounts for half of all coronavirus genomes sequenced around the world since the start of the pandemic.

When they looked at the new variant, researchers found it had 23 mutations, 17 of which could have an effect on the virus’s behavior, including some on the spike protein that other research has shown can help the virus penetrate cells more effectively than previous variants. .

Despite the findings, many researchers say more needs to be done to find out if the changes have a real impact.

“The new variant is concerning, but there is still a lot we don’t know,” said Angela Rasmussen, a virologist at the Center for Global Health Science and Security at Georgetown University. “I don’t think we can draw any conclusion on this, except that we need to look at this more.”

One of the things researchers should investigate, several said, is whether the new variant is more sticky and attaches to and penetrates cells more easily than other variants. Scientists also need to investigate whether cells infected with the new variants produce more virus and whether infected animals transmit the virus more easily to uninfected animals.

“The molecular studies to really accurately measure transmittance have not been done,” said Bettie Steinberg, virologist and provost at Northwell Health’s Feinstein Institutes for Medical Research. “Viruses are constantly mutating.”

This wouldn’t be the first time that a new variant supplanted others during the pandemic, health experts said. Earlier this year, another variant – one that showed up in Europe that also had a peak protein mutation – replaced the original Wuhan variant as the world’s most common.

Lab studies showed that the variant from Europe was better at infecting cells and transferring animals between animals.

However, that variant only had one change in the spike protein that could affect its function, said Vineet Menachery, a coronavirus expert at the University of Texas Medical Branch. The protein helps the virus enter and infect cells.

The new British variant has nearly two dozen mutations in all, according to the team that mapped it. Eight of these are in the spike protein gene. Several of the mutations can affect transmission, said Dr. Menachery.

Scientists found in a separate study that similar peak protein changes facilitated viral access to cells in laboratory experiments and transfer in animal models.

Scientists said they weren’t sure how a constellation of mutations would affect the virus’s ability to infect cells and spread, but said they doubted the changes were enough to make current vaccines ineffective.

A Pfizer spokeswoman said the gene-based technology that produced the vaccine has the flexibility to change the RNA sequence in the vaccine to cover new variants of the virus should one emerge that is not well covered by the current one. vaccine.

Pfizer and partner BioNTech SE have tested blood samples from people immunized with the vaccine for their ability to neutralize multiple mutant variants, the spokeswoman said. To date, the companies have found consistent coverage of all variants tested.

The companies are now generating data on how well blood samples from people immunized with their vaccine can neutralize the new variant from the UK

—Sarah Toy and Bojan Pancevski contributed to this article.

Write to Daniela Hernandez at [email protected], Joanna Sugden at [email protected], and Betsy McKay at [email protected]