New coronavirus strain divides scientists as UK and others act to reduce the spread

Transmissibility – how easily the virus spreads from one person to another – and the severity of the disease it causes are both important values ​​for measuring the potential threat. And scientists say there are still many things I don’t know.

Viruses move naturally, especially RNA viruses, such as the new coronavirus. Many variants of the new coronavirus have surfaced since racing 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 current rise in infections in US

He said he did not think the US should stop flights from the UK, but that “I think you might want to consider asking people boarding a plane and flying from England to be tested.” in the last 48 to 72 hours. “

Dozens of countries around the world have moved to reduce travel in the UK. The US does not. New York has asked airlines to ask all UK passengers to take a negative Covid-19 test before boarding flights to the state.

Health experts and drug industry officials say the newly authorized vaccines, which induce virus-spreading responses targeting different areas of the pathogen’s surface, are expected to protect against the new variant.

Ugur Sahin, executive director of BioNTech SE,

who collaborated with Pfizer Inc. for a vaccine, he said on 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 effective in infecting people, we may even need a higher vaccination rate to ensure that normal life can go on without interruption,” he said.

However, David Dowdy, an epidemiologist at the Johns Hopkins School of Public Health, said higher vaccination rates would not be needed, even if the vaccine proves more transmissible as long as enough people are inoculated.

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

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

British scientists analyzed how often the new variant was detected, whether changes in its replication could make it more transmissible, and what data showed the correlation between increasing the number of cases and increasing the detection of the new variant.

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

However, he added, more research was needed to find out how transmissible the biology behind it is. “We still don’t understand the exact biological mechanisms of this, there is still a lot of uncertainty about exactly how it occurs, exactly at the level of additional transmissibility.”

British scientists actively monitored virus mutations and sequenced the genome of 160,000 new coronavirus samples, or 10% of all cases of Covid-19 in the country. That being said, British researchers say their work accounts for half of all coronavirus genomes sequenced worldwide since the beginning of the pandemic.

While looking at the new variant, the researchers found that it has 23 mutations, 17 of which could have an effect on the behavior of the virus, including some on the spike protein that other research has found could help the virus penetrate. in cells more efficiently than previous variants. .

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

“The new option is worrying, but there are still many things we don’t know,” said Angela Rasmussen, a virologist at Georgetown University’s Center for Global Health Science and Safety. “I don’t think we can come to any conclusions in this regard, other than that we need to look at this more.”

Among the issues that researchers need to research, several said, is whether the new variant is more sticky and attaches and enters cells more easily than other variants. Scientists also need to study whether cells infected with the new variants produce more virus and whether infected animals transmit the virus more easily to uninfected ones.

Molecular studies to really accurately measure transmissibility have not been done, said Bettie Steinberg, virologist and head of the Northwell Health Feinstein Institute for Medical Research. “Viruses move all the time.”

This would not be the first time a new variant has crowded others during the pandemic, health experts said. Earlier this year, another variant – one that appeared in Europe, which also had a spike-protein mutation – replaced the original one in Wuhan as the most widespread in the world.

Laboratory studies have shown that the European variant is better at infecting cells and transmitting animals.

However, that variant had a single spike protein modification that could affect its function, said Vineet Menachery, a coronavirus expert at the University of Texas. The protein helps the virus enter and infect cells.

The new British variant has almost two dozen mutations in total, according to the team that mapped it. Eight of them are in the spike protein gene. More of the mutations could affect transmission, Dr. Menachery said.

The scientists found in a separate study that similar changes in the spike protein facilitated viral entry into cells in laboratory experiments, as well as transmission in animal models.

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

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

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

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

—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]