ATLANTA (CNN) – A mutation that could allow COVID-19 to escape antibody protection has now been found in samples from a fast-growing strain in the UK, according to a report released Monday by Public Health England.
The mutation, called E484K, has already been part of the genetic signature of variants related to South Africa and Brazil.
According to the PHE report, the mutation was recently detected in at least 11 samples from strain B.1.1.7 in the UK. It also appears that some of these samples acquired this mutation independently, rather than spreading from a single case.
This could mean that a variant already known to be more transmissible may also become somewhat resistant to the immune protection provided by vaccines or more likely to cause reinfection among people who have previously been infected, experts say.
“This doesn’t seem like great news for the vaccine’s effectiveness,” said Joseph Fauver, an associate researcher in epidemiology at Yale School of Public Health.
He added that the new finding is also something to monitor in the US, where efforts to look for variants through genetic sequencing have lagged behind the UK. surveillance program, “Fauver said.
Evidence of immune escape
Experts say it is too early to predict whether this development will have a significant impact on the trajectory of COVID-19 in the UK and around the world.
However, there is some research that suggests that E484K may be a key culprit behind why some vaccines appear to be 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% in a separate Phase 2b study in South Africa. Similarly, in the Johnson & Johnson Phase 3 study, efficacy differed across countries: 72% in the US versus 57% in South Africa. In both studies, 90-95% of cases in South Africa were related to variant B.1.351, which contains the E484K mutation.
But much of the early evidence for this so-called “escape mutant” comes from laboratory research, which shows that antibodies appear to be less able to bind mutated peak proteins.
The most recent example comes from a new study that found that antibodies in vaccinated people were less effective in neutralizing a synthetic virus similar to the one in the PHE report – which means they contained essential mutations in B.1.1.7, plus E484K.
The addition of the E484K mutation appears to increase the bar for the level of antibodies needed to prevent the laboratory-produced virus from infecting cells, compared to the B.1.1.7 mutations themselves.
The study took blood from 23 people who received a single dose of Pfizer / BioNTech vaccine three weeks earlier, with a median age of 82 years. The study could not demonstrate how this influenced the real likelihood of people becoming infected with virus variants.
Citing the GISAID genomics database, the study also recorded a slightly higher number of cases than the PHE report: two unrelated cases in Wales and a group of over a dozen in England, which appeared in the first half. of December 2020.
More important vaccines than ever
Paul Bieniasz, a virologist at Rockefeller University, said the E484K mutation “appeared sporadically” in several samples for months, but until recently it does not appear to give the virus an advantage in populations without pre-existing immunity.
But it’s a different story in places like South Africa, where many people had been previously infected. On Monday, Dr. Anthony Fauci noted “a very high rate of reinfection to the point where the previous infection does not seem to protect you,” citing the work of colleagues in South Africa.
The B.1.1.7 strain first identified in the UK has now been found in at least 70 countries around the world, including about 470 known cases in the US, according to the US Centers for Disease Control and Prevention.
Experts say that aggressive testing, compliance with COVID-19 guidelines and the rapid launch of vaccines are more important than ever in light of these spreads.
“We need to vaccinate as many people as possible,” Fauci said earlier. “Even if there is diminished protection against variants, there is enough protection to prevent you from suffering from serious illnesses, including hospitalization and death.”
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