ATLANTA (CNN) – According to a report Monday by Public Health England, a mutation that could allow COVID-19 to escape antibody protection has now been found in samples from a rapidly spreading strain in the UK.
The mutation, called E484K, was already part of the genetic signature of variants associated with South Africa and Brazil.
According to the PHE report, the mutation has been newly detected in at least 11 samples of the British B.1.1.7 strain. 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 known to be more transmissible is also at risk of becoming somewhat resistant to the immune protection offered by vaccines, or more likely to be reinfected in people who have been previously infected, experts say.
“This doesn’t seem like good news for vaccine efficacy,” said Joseph Fauver, associate research scientist in epidemiology at the Yale School of Public Health.
He added that the new finding is also something to keep an eye on in the US, where attempts to look for variants through genetic sequencing are lagging behind the UK. 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 COVID-19’s trajectory in the UK and around the world.
However, there is some research to suggest that E484K may be a major culprit behind why certain 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 was found to be only 60% effective in a separate Phase 2b study conducted in South Africa. Likewise, efficacy in Johnson & Johnson’s Phase 3 trial differed by country: 72% in the US versus 57% in South Africa. In both studies, 90 to 95% of cases in South Africa were linked to the B.1.351 variant, which contains the E484K mutation.
But much of the early evidence for this so-called “escape mutant” comes from laboratory research showing that antibodies seem less able to bind spike proteins created by the mutation.
The latest example comes from a new study that found antibodies from vaccinated humans were less effective at neutralizing a synthetic virus similar to the one in the PHE report – meaning they contain crucial mutations of B.1.1.7, plus E484K.
The addition of the E484K mutation seemed to raise the bar for the level of antibodies needed to prevent the lab-made virus from infecting cells, compared to B.1.1.7 mutations alone.
The study sampled blood from 23 people who had received a single dose of the Pfizer / BioNTech vaccine three weeks earlier, with an average age of 82 years. The study could not show how this affected people’s true likelihood of getting infected with virus variants.
With reference to the genomics database GISAID, the study also counted a slightly higher total number of cases than the PHE report: two unrelated cases in Wales and a cluster of more than a dozen in England, which were already in the first half of published in December 2020.
Vaccines more important than ever
Paul Bieniasz, a virologist at Rockefeller University, noted that the E484K mutation appeared “sporadically” in multiple samples for months, but until recently the virus did not appear to be of benefit in populations without pre-existing immunity.
But it’s a different story in places like South Africa, where many people were previously infected. On Monday, Dr. Anthony Fauci noted “a very high rate of reinfection to the point where previous infection does not seem to protect you,” citing the work of colleagues in South Africa.
The B.1.1.7 strain first observed 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 aggressive testing, adhering to COVID-19 guidelines, and rapid vaccine rollout are more important than ever in the face of these spreading variants.
“We need to get as many people vaccinated as soon as possible,” Fauci said earlier. “Even though there is reduced protection against the variants, there is enough protection to prevent you from developing serious illness, including hospitalization and deaths.”
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