London and much of southeastern England went into lockdown as scientists in the U.K. released more information on a newly identified variant of the coronavirus that appears to be more contagious than the original. Nations have banned travel from the U.K. as more areas plan to join the lockdown Saturday.
The new mutations
The variant has 17 mutations compared with its most recent ancestor, which is an unusually large number. One explanation for the high number of mutations is the variant may have emerged in a patient that had the virus in their system for a long time, commonly referred to as a COVID-19 “long hauler.” With longer time, the virus can accumulate a large number of mutations.
Several of the new mutations affect the so-called “spiked protein“ on the virus surface that attaches to human cells. Some mutations may increase how tightly the protein binds to the ACE2 receptor, its entry point into human cells, likely making it easier for the virus to get inside.
The variant appears to be better at spreading between people. According to the models, it has an increased transmission rate of 70% compared with other variants in the U.K. However, there is no evidence that this variant causes more severe illness or increased risk of death.
It was first spotted in September in southeastern England. The new variant accounted for a quarter of cases in London by November. By the week of Dec. 9, it was responsible for 60 percent of cases in the city. Currently, the cases are concentrated in London and eastern England.
Although the new variant has not been identified through genetic sequencing in the U.S., it could already be here undetected, according to the U.S. Centers for Disease Control and Prevention.
Scientists have identified a similar version of the virus in South Africa. It shares some of the mutations seen in the British variant. That version of the virus has been found in up to 90% of the samples whose genetic sequences have been analyzed since mid-November.
The British government confirmed Wednesday that the variant of the novel coronavirus identified in South Africa has emerged in the U.K. as well. The two cases are contacts of people who traveled to South Africa.
Over 40 countries have banned travelers from the U.K. in the response to the news about the new variant. Some countries placed restrictions on travel allowing some U.K. travelers in.
The United States had not issued a ban on travel from the U.K. as of Thursday morning. However, Virgin Atlantic will require proof of a negative COVID-19 test for all passengers traveling from London to the U.S. starting Dec. 24. New York Gov. Andrew Cuomo called on the federal government to halt flights from the U.K. British Airways, Virgin Atlantic and Delta Airlines have agreed to test all passengers before they enter New York.