The UK coronavirus variant is now in at least nine states in the United States, and scientists expect that number to increase soon.
A total of 63 infections with the strain known as B.1.1.7 were reported to the Centers for Disease Control and Prevention on Friday, the most recent data available. Given the limited amount of genetic testing conducted on coronavirus samples collected here, health officials say the true number of cases is certainly greater.
California currently has more confirmed cases than any other state, with 32, according to the CDC. Florida comes next with 22.
Colorado, the first state where the UK variant was first detected, now has three cases. Connecticut has two cases, and Georgia, New York, Pennsylvania and Texas each, says the CDC.
In addition, the Minnesota Department of Health announced on Saturday that five cases involving the UK variant had been detected there.
This version of the coronavirus has a distinct set of 17 genetic alterations that differentiate it from its predecessors. It was first detected in two British residents in September.
UK scientists warned that their local variant was up to 70% more transmissible than previous versions of the virus. Prime Minister Boris Johnson responded by renewing the blockade measures in much of England, despite the approaching Christmas holiday, and several countries – including the United States – have restricted UK travel.
It is now clear that these measures came too late. Variant B.1.1.7 has been detected in 49 countries so far, including some as far away from the UK as Australia, Chile and Japan.
Many scientists outside the United Kingdom were initially skeptical that this version of the virus was more infectious than its predecessors. There were a number of other potential explanations for its spread in England, they said.
One possibility was that the variant encountered a particularly vulnerable group of people – perhaps older people or those with an unusually high rate of underlying health problems. It also has the fact that it took root at a time when people spent more time indoors, where transmission is easier.
Early laboratory tests suggested that the variant was more transmissible in mice, but it was unclear whether these results were meaningful to people.
Now, UK scientists have reinforced their case. They used genetic data to mark the spread of B.1.1.7 in three distinct regions of England and found similar growth patterns in all of them. Another type of genetic screening provided a separate signal that B.1.1.7 was consistently able to outperform its competitors.
Mathematical models also showed that the way the variant spread across different regions was too similar to be a coincidence – it had to be that the virus itself was more transmissible.
In fact, according to its updated calculations, B.1.1.7 is about 56% more transmissible than previous versions of the coronavirus. And while a month of business closings, masking mandates and meeting limits in Britain were sufficient to stop the growth of other strains of the coronavirus, these stringent public health measures have not prevented the rapid growth of B.1.1.7 among the British.
The new research has not yet been examined by the typical peer review process. But scientists who were not involved in the work said the new data was much more convincing.
“This is pretty solid evidence that this is actually a faster-spreading virus,” said Vladimir Minin, a biostatistician at UC Irvine.
There is still no evidence that the UK strain infects people more quickly, makes them sicker or increases the risk of death. And the researchers remain confident that the COVID-19 vaccines developed so far are effective against the variant, despite its genetic changes.
But considering the precarious work the US has done to contain the coronavirus so far, the emergence of a more transmissible strain is certainly a cause for concern.
The US accounts for about 4% of the world population, but accounts for almost 25% of all coronavirus cases and more than 19% of deaths from COVID-19, according to data from Johns Hopkins University. This record does not leave scientists optimistic that Americans will be able to contain B.1.1.7.
“We are losing the race with the coronavirus,” said Derek Cummings, an expert on emerging pathogens at the University of Florida. “Now there is this variant that will make the race even more difficult.”
You can follow the spread of B.1.1.7 in the United States on the CDC website.