VOA慢速英语--英国和南非发现新型变异的新冠病毒（在线收听）

New Type of Coronavirus Identified In Britain, South Africa

A new kind, or strain, of the coronavirus has been found in Britain and South Africa.

Health experts in Britain and the United States say the new strain seems to infect more easily than others. However, there is no evidence showing it to be more deadly.

Patrick Vallance is the British government's chief scientific adviser. He said the new strain "moves fast and is becoming the" stronger strain. By the end of December, it is estimated that it will have caused over 60 percent of infections in London.

It is unclear if this new strain causes a more severe form of COVID-19.

Will the current vaccines work on the new strain?

Vaccinations have already started in some parts of the world. So, the question many people are asking is this: Will the current vaccines protect people against the new strain of virus?

One of the companies making an approved vaccine, Germany's BioNTech, recently gave a response. The Associated Press reported Tuesday that the company's chief said he is confident that its coronavirus vaccine works against the new UK strain.

CEO Ugur Sahin spoke at a news conference the day after the vaccine was approved for use in the European Union. He said, "... scientifically, it is highly likely that the immune response by this vaccine also can deal with the new" strain of virus.

The proteins on the UK strain, Sahin explained, are 99 percent the same as on the existing strains. Therefore, BioNTech has "scientific confidence" that its vaccine will be effective.

However, he noted that "further studies are needed to be completely sure."

"We don't know at the moment if our vaccine is also able to provide protection against this new" strain of the coronavirus. He added that he and his team will need about two weeks to do the additional experiments.

Vivek Murthy, the surgeon general nominee for President-elect Joe Biden, offered his answer Sunday on CBS News. He said recently there is "no reason to believe that the vaccines that have been developed will not be effective against this virus as well."

Dr. Moncef Slaoui is the chief science adviser for the U.S. government's vaccine distribution effort. He said Sunday on the Cable News Network (CNN) that the possibility that new strains will be resistant to existing vaccines is low. But, he added, the possibility exists.

Genetics expert Trevor Bedford agreed. Bedford is a biologist and genetics expert at the Fred Hutchinson Cancer Research Center in Seattle, Washington.

"I'm not concerned," he wrote on his Twitter page.

He added that many changes in the genetic code would probably be needed to weaken a vaccine, not just one or two mutations. But vaccines may need to be changed over time as these mutations continue. And the changes, he wrote, should be more closely observed.

Reaction to new strain

Over the weekend, British Prime Minister Boris Johnson announced new restrictions because of the new strain. Several European Union countries and Canada were banning or limiting flights from Britain to try to limit any spread.

Experts say the new strain does not change public health guidance to wear masks, wash hands and keep social distance.

Viruses naturally evolve, or change, as they move through the population. Some viruses evolve more than others. This is one reason why scientists need to develop a new flu shot each year.

Changes on spiky protein

Since first identified in China one year ago, researchers have been seeing new strains of the virus that causes COVID-19.

The newly identified strain of the coronavirus has many mutations. Some of these mutations are on the spiky protein. The virus uses these spikes to attach to cells and infect them. Current vaccines target these spikes.

Dr. Ravi Gupta told The Associated Press, "I'm worried about this, for sure." He studies viruses at the University of Cambridge in Britain. Gupta said it is too soon to know the importance of this new information.

How do these new strains happen?

Through normal evolution, viruses often change in small ways.

A bigger worry, however, is when a virus mutates by changing the protein on its surface. They do this to help it escape drugs or attacks from the immune system.

New evidence suggests that may be starting to happen with the coronavirus, Trevor Bedford wrote on Twitter. Bedford also noted that we are now seeing the rise and spread of several new strains. Some, he added, are showing "resistance to antibody treatments."

This has led to another question: Will people who had COVID-19 from an old strain be able to get the new one?

Gupta says that is "unlikely."

Scott Gottlieb is former commissioner of the U.S. Food and Drug Administration. In a recent television appearance recently on CBS News, he agreed with Gupta's prediction.

Words in This Story

strain – n. a group of closely related living things that look similar but possess one or more unique characteristics

mutation – n. a change in a gene or the resulting new trait it produces in an individual

spiky – adj. having sharp points : formed into points

antibody – n. medical : a substance produced by the body to fight disease

distribution – n. the act of giving or delivering something to people

genetic code – n. the arrangement of chemical groups within the genes which specify particular kinds of amino acids used to make proteins

response –n. an answer or reaction to something

immune –adj. to not be affected by disease