ATLANTA (CNN) – A mutation that could allow COVID-19 to escape protection from the antibody has now been found in samples of a rapidly spreading strain in the UK, according to a report published Monday by Public Health England.
The mutation, called E484K, was already part of the genetic signature of variants linked to South Africa and Brazil.
According to the PHE report, the mutation was recently detected in at least 11 samples of the B.1.1.7 strain in the United Kingdom. It also appears that some of these samples may have acquired this mutation independently, rather than spreading from a single case.
This could mean that a variant already known to be more transmissible is also at risk of becoming somewhat resistant to the immunological protection offered by vaccines, or more likely to cause reinfection among people who have already been infected, experts say.
“This does not seem to be great news for the vaccine’s effectiveness,” said Joseph Fauver, associate researcher in epidemiology at the Yale School of Public Health.
He added that the new discovery is also something that should be monitored in the US, where efforts to look for variants through genetic sequencing have lagged behind the UK. The fact that we only saw this in the UK “may be the result of its robust genomics surveillance program,” said Fauver.
Evidence of immune escape
Experts say it is too early to predict whether this development will have a major impact on the trajectory of COVID-19 in the UK and around the world.
However, there is some research suggesting that E484K may be the main culprit for why certain vaccines appear less effective in South Africa.
Novavax recently announced that its vaccine was 89% effective in its Phase 3 study in the UK, but appeared only 60% effective in a separate Phase 2b study conducted in South Africa. Likewise, in the Phase 3 trial of Johnson & Johnson, effectiveness differed by country: 72% in the United States versus 57% in South Africa. In both trials, 90 to 95% of cases in South Africa were associated with variant B.1.351, which contains the mutation E484K.
But much of the first evidence of this so-called “escape mutant” comes from laboratory research, showing that antibodies appear less able to bind to peak proteins resulting from the mutation.
The most recent example comes from a new study that found that antibodies from vaccinated people were less effective in neutralizing a synthetic virus similar to those in the PHE report – that is, they contained essential mutations from B.1.1.7 in addition to E484K.
Adding the E484K mutation seemed to increase the level of antibodies needed to prevent the laboratory-made virus from infecting cells when compared to B.1.1.7 mutations on their own.
The study collected blood samples from 23 people who received a single dose of the Pfizer / BioNTech vaccine three weeks earlier, with an average age of 82 years. The study was unable to demonstrate how it affected people’s real likelihood of becoming infected with variants of the virus.
Citing the GISAID genomic database, the study also recorded a slightly larger number of cases than the PHE report: two unrelated cases in Wales and a group of more than a dozen in England, appearing already in the first half of December 2020.
More important vaccines than ever
Paul Bieniasz, a virologist at Rockefeller University, noted that the E484K mutation “appeared sporadically” in several samples for months, but until recently it did not appear to offer the virus an advantage in populations without pre-existing immunity.
But it is a different story in places like South Africa, where many people have already been infected. On Monday, Dr. Anthony Fauci observed “a very high rate of reinfection to the extent that a previous infection does not seem to protect him”, citing the work of colleagues in South Africa.
The B.1.1.7 strain first detected in the United Kingdom has now been found in at least 70 countries worldwide, including about 470 known cases in the United States, according to the US Centers for Disease Control and Prevention.
Experts say aggressive testing, adherence to the COVID-19 guidelines and the rapid launch of vaccines are more important than ever, in light of these variants of spread.
“We need to vaccinate as many people as soon as possible,” said Fauci earlier. “Even though there is reduced protection against variants, there is enough protection to prevent you from contracting serious illnesses, including hospitalization and deaths.”
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