A mutation that could allow Covid-19 to escape antibody protection has now been found in samples of a rapidly spreading strain in the United Kingdom, according to a report by Public Health England on Monday.
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 to be monitored in the United States, where efforts to look for variants through genetic sequencing have been left behind in the United Kingdom. The fact that we only saw this in the UK “may be the result of its robust genomic surveillance program,” said Fauver.
Experts say it is too early to predict whether this development will have a major impact on Covid-19’s trajectory in the UK and around the world.
Previous studies suggest that E484K may be the main culprit why certain vaccines appear less effective in South Africa. Laboratory research has also shown that antibodies appear less able to bind and neutralize spike proteins resulting from the mutation.
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
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 point that a previous infection does not seem to protect you”, 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 that aggressive testing, adherence to Covid-19 guidelines and the rapid launch of vaccines are more important than ever, in light of these spread variants.
“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.”