The first case in the United States of the most contagious coronavirus variant that was first discovered in Britain was found in Colorado on Tuesday, said Governor Jared Polis, raising the worrying possibility that the variant is already well established in the community. patient – and maybe somewhere else.
“He did not teleport across the Atlantic,” said William Hanage, an epidemiologist at the Harvard TH Chan School of Public Health.
The variant was detected in a man in his 20s with no travel history, Polis said. The man was isolated in Elbert County, southeast of Denver, he said.
Dr. Hanage said the newly reported case “should not be a cause for panic.” But, he added, “it is a reason to redouble our efforts to prevent the virus from having the opportunity to spread,” he said.
Scientists are concerned about the variants, but are not surprised by them. It is normal for viruses to mutate, and most coronavirus mutations have proven to be minor. There is no evidence that an infection with the variant – known as B.1.1.7 – is more likely to lead to a severe case of Covid-19, increase the risk of death or avoid new vaccines.
But the speed at which the variant appears to spread can lead to more infections – and, therefore, more hospitalizations.
The case identified on Tuesday came from Elbert County, Colorado, which has a population of about 27,000. Colorado cases, deaths and hospitalizations have been falling steadily in recent weeks.
“There is a lot we don’t know about this new Covid-19 variant, but scientists in the UK are warning the world that it is significantly more contagious,” said Polis. “The health and safety of the coloradans is our highest priority and we will closely monitor this case, as well as all Covid-19 indicators.”
The Centers for Disease Control and Prevention said in a statement on Tuesday that it expects “there will be additional cases that are likely to be detected in the next few days”.
It is not clear where B.1.1.7 emerged. Britain has the largest coronavirus genome sequencing system, which may be why the variant was first found there.
Earlier this month, British researchers noted that the variant was becoming more prevalent in parts of Britain. His subsequent investigations suggest that the variant spreads more readily than others in circulation.
It is also not clear why B.1.1.7 transmits more easily. The strain has accumulated 23 mutations since it separated from other coronaviruses. Researchers are investigating some of the mutations to see if they allow viruses to invade cells more quickly or make more copies of themselves.
Prime Minister Boris Johnson raised the alarm about the spread of the variant in England on December 19. He responded to the emergence of B.1.1.7 by imposing stronger restrictions on people’s movements and the size of meetings.
Much of the south and east of England, including London, is under the highest level of restrictions. The rules require people to stay at home, except for urgent trips, medical appointments and outdoor exercises. And the British Army was mobilized to help the National Health Service, the country’s health care system, set up sites to administer rapid tests of coronavirus to drivers, going from truck to truck for testing.
“When the virus changes its method of attack, we must change our method of defense,” said Johnson at the time. “We have to act on the information we have, because now it is spreading very fast.”
Fears that the variant would spread from Britain last week prompted much of Europe to isolate the United Kingdom. As part of that effort, France imposed a 48-hour blockade on the British border, which created chaos on both sides of the English Channel and warned Britain that some fresh produce could be scarce for a short time.
At the end of last week, more than 50 governments imposed restrictions.
A new rule in the United States requiring travelers arriving from Britain – including American citizens – to provide proof of a negative coronavirus test at the entrance was announced on Thursday and took effect on Monday.
But experts noted that the first British samples of B.1.1.7 dated back to September. It was likely that the variant had already spread across countries.
It looks like they were right. Cases of the variant have been identified in more than a dozen countries worldwide. Health officials in Ontario, Canada, said on Saturday that they had identified two cases of the variant in a couple with no known travel or exposure history.
The United States sequences far fewer genomes than Britain, which has led American scientists to suspect that the variant could also be in the country undetected. On Tuesday, the United States joined the ranks of nations with B.1.1.7.
Dr. Hanage said the United States would have to improve the way it monitors the genetic sequences of circulating viruses to track their spread. It is conceivable that the new variant may have fueled recent outbreaks in the Midwest and Rhode Island, for example, but scientists do not know why public health officials have not been tracking viruses carefully enough across the country.
“The United States is hampered by the inconsistency of its approach,” he said. “Unless we turn on the lights, we won’t know it’s there.”
Because B.1.1.7 appears to be much more contagious than other strains, British researchers have warned that current restrictions in the UK may not be sufficient. In a preliminary study, they found that schools may need to be closed and vaccination programs accelerated aggressively to prevent a sudden increase in cases.
If B.1.1.7 takes off in the United States, it is possible that vaccination will also have to be accelerated there. But in the first two weeks, the US vaccination program is progressing more slowly than expected.
“You need to be able to get as many barriers to transmission as you can as quickly as possible,” said Hanage.
Nicholas Davies, an epidemiologist at the London School of Hygiene and Tropical Medicine, said in an interview last week that it was clear “that a faster vaccination will be something really important for any country that has to deal with this or similar variants. “