But the CDC said there was no evidence yet.
“Based on the scientific understanding of viruses, it is very likely that there are many variants that are developing simultaneously around the world,” a spokesman said in an email to CNN.
“Furthermore, there is a high probability that there will be options in the United States; however, it could take weeks or months to determine if there is a variant of the virus that causes COVID-1
“Researchers have observed strains in the United States since the beginning of the pandemic, including 5,700 samples collected in November and December. To date, neither CDC researchers nor analysts have seen the emergence of a particular variant in the United States, as seen with the B. 1.1.7 in the United Kingdom or B.1.351 in South Africa. “
It was not clear why the White House issued a press release to countries speculating on a new version of the virus that originated in the United States. A spokesman for the administration told CNN’s Jim Acosta that the speculation began during a conversation with governors.
CNN received multiple copies of written statements sent to the states last week.
“This fall / winter jump is almost twice as high as the spring and summer jumps. This acceleration suggests that a US version may appear here, in addition to the UK version that is already spreading in our country. communities and can be 50% more transferable, ”the report said.
“Aggressive mitigation must be used to combine with a more aggressive virus; without the uniform application of effective facial masking (two or three layers and well-fitting) and strict social distancing, epidemics can quickly worsen as these variants spread and become predominant.
The CDC is tracking cases of the variant, first seen in the UK. Regular coronavirus testing does not tell doctors if people are infected with the variant. To do this, laboratories need to conduct far more detailed genomic tests.
So far, the CDC said Friday that 63 cases of people infected with a variant similar to the one found in the UK have been reported in eight states: California, Colorado, Connecticut, Florida, Georgia, New York, Pennsylvania and Texas. However, the CDC says there are likely to be many more cases.
It is unclear whether these options, which can make it easier for people to transmit the virus to others, stimulate the explosive spread of the virus in the United States, parts of Europe and elsewhere.
All viruses mutate and the coronavirus mutates at a relatively slow rate compared to, say, influenza. Researchers track changes in the virus as it spreads around the world, and release their findings into public databases such as NextStrain and one called GISAID.
Academic researchers also said they were puzzled by the White House statement and said there was still no evidence that the variants of the virus stimulated the spread of the virus in the United States.
“I don’t know of an option that has been identified in the United States that is responsible for the growth we’re seeing,” Scott Hensley, a virus and immunity expert at the University of Pennsylvania, told CNN.
“There are many reasons why infection rates have increased in the fall and winter,” Hensley added. These include lower temperatures, which drive people indoors and which can also create drier, cooler air that helps viruses spread.
“The increase in cases does not necessarily need a genetic explanation,” he said.
Trevor Bedford of the University of Washington and the Fred Hutchinson Cancer Research Center, which helps maintain NextStrain, also said he saw no evidence of a US-born strain spreading more aggressively.
“We don’t see any indication of a specific line or option contributing to the huge number of cases in the fall / winter in the U.S. epidemic,” said Bedford, who is investigating the spread of viruses.
“There is no single specific line that can grow and become a major part of the epidemic quickly (as seen in Britain and South Africa).”
This is not to say that there are no variants emerging in the United States – coronaviruses, like many viruses, change over time and the more they are transmitted. But no specific version has been taken to change the rate of spread, the researchers said.
The more the virus spreads, the more likely it is to happen, Hensley said.
“If you’re a virus and you have 300,000 shots to the door every day, there’s a good chance one of those shots will come in. Viruses are constantly making mistakes in their genomes,” he said.
“The levels of the virus in our country are out of control,” he added.
“If there are a lot of viruses, there are a lot of options. If someone is worried about options, the best thing you can do is limit the amount of virus circulating. The best way you can do that this is through vaccination of people and social distancing. “