EDITOR’S NOTE: (8 January 2021, 8 pm Eastern Time): After an earlier version of this article was published, the Centers for Disease Control and Prevention issued a statement saying that they had not seen the emergence of a new American variant of the coronavirus, although they noted that there may be many variants emerging around the world. The New York Times reported that the suggestion of a highly contagious new US variant was based on speculation by Dr. Deborah Birx and was contested by the CDC. NBC News did not confirm this report and Dr. Birx declined to comment when contacted by NBC News. The article has been updated to reflect these developments.
A report from the White House coronavirus task force said the explosive increase in coronavirus cases in the United States in recent months may be caused by a more contagious American variant of the virus. But a separate statement from the Centers for Disease Control and Prevention said its researchers did not see the emergence of an American variant.
“This fall / winter wave was almost twice the rate of increase in cases compared to spring and summer,” according to the White House task force document, which was sent to the states. “This acceleration suggests that there may be a US variant that has evolved here, in addition to the UK variant that is already spreading in our communities and may be 50 percent more communicable.”
The CDC’s statement, however, was much more skeptical about this possibility. It is likely that there are many variants of the coronavirus worldwide, the statement said, but “so far, neither CDC researchers nor analysts have seen the emergence of a particular variant in the United States, as seen with the emergence” of variants in the UK or South Africa.
The New York Times reported that the task force hypothesis was the result of speculation by Dr. Deborah Birx, the White House coronavirus coordinator, and said the CDC had urged her not to include speculation in the document. Contacted by NBC News, Dr. Birx declined to comment.
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The task force document, which was also posted online by the state of Kentucky, does not identify a specific new strain or confirm that one has been detected in the United States. Instead, the document suggests that the possibility of a new strain could potentially explain the rapid acceleration in cases in recent months.
The document, dated Sunday, January 3, comes at a time when states across the country are detecting cases of the UK’s most contagious variant. In the UK, the rapid spread of this variant, known as B.1.1.7, has put the country in a strict block this week as cases have increased.
In the US, cases started to increase in the fall. The daily case count reached 200,000 on December 6, and the daily average has surpassed that number since then, according to data from NBC News.
“I would be surprised if there were no new variants appearing in the United States,” said Dr. Richard Besser, former acting director of the Centers for Disease Control and Prevention and current president of the Robert Wood Johnson Foundation. Besser is not a member of the White House coronavirus task force.
If any of these variants somehow caused the virus to spread more easily or silently, Besser said it would be “yet another reason why we need to follow public health advice: social distance, washing hands, wearing masks and avoiding those situations in that we know that viruses spread more easily, as in closed enclosed spaces. “
In fact, the document again emphasizes the need for preventive efforts to delay the spread.
“Aggressive mitigation must be used to match a more aggressive virus; without the uniform implementation of an effective face mask (two or three layers and well adjusted) and strict social distance, epidemics can worsen rapidly as these variants spread and become prevalent, ”he says, referring to the Kingdom variant. United Kingdom and the potential US variant.
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A member of the task force confirmed the document’s authenticity to NBC News.
Coronavirus mutations are common, and a new mutation is introduced every two weeks, according to the CDC.
The more widespread a virus is, the more opportunities it has to mutate, scientists say.
“The more we don’t restrict the spread, the more opportunities the virus will have to evolve,” said Gigi Kwik Gronvall, a senior scholar at the Johns Hopkins Center for Health Safety, in an earlier interview with NBC News.
The coronavirus has probably mutated thousands of times since the original strain appeared in Wuhan, China in late 2019, said Brian O’Roak, a human geneticist at Oregon Health & Science University. Samples of the virus in O’Roak’s lab mutated 15 to 20 times compared to the original strain, he said.
Even for variants that become more common, most of the time the changes are silent, which means that they are small changes in the genetic code of the virus and do not affect its behavior. But other mutations, like those in the UK variant, can be significant and affect the behavior of the virus.
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Lauren Dunn and Monica Alba contributed.