UK coronavirus strain detects mutation that could impact vaccines, experts say


ATLANTA (CNN) – A mutation that could allow COVID-19 to escape antibody protection has now been found in samples of a rapidly spreading strain in the UK, according to a report released 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 newly detected in at least 11 samples of the UK strain B.1.1.7. It also appears that some of these samples may have acquired this mutation independently, instead of 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 immune protection offered by vaccines, or more likely to cause reinfection in people previously infected, experts say.

“This doesn’t sound like great news for vaccine 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 watch out for in the United States, where efforts to find variants through genetic sequencing have lagged behind in the United Kingdom. surveillance program, ”Fauver said.

Evidence of immune leakage

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, some research suggests that E484K may be a major contributor to why some vaccines appear to be less effective in South Africa.

Novavax recently announced that its vaccine was 89% effective in its Phase 3 trial in the UK, but only appeared to be 60% effective in a separate Phase 2b study in South Africa. Likewise, in the Johnson & Johnson Phase 3 trial, efficacy was different across countries: 72% in the United States versus 57% in South Africa. In both trials, 90-95% 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 the antibodies appear less able to bind to the spike proteins resulting from the mutation.

The latest example comes from a new study which found that the antibodies of vaccinated people were less effective at neutralizing a synthetic virus resembling those in the PHE report – meaning they contained pivotal mutations of B.1.1.7, more E484K.

Adding the E484K mutation appeared to raise the bar for the level of antibodies needed to prevent the lab-made virus from infecting cells, compared to the B.1.1.7 mutations alone.

The study sampled the blood of 23 people who had received a single dose of Pfizer / BioNTech vaccine three weeks earlier, with a median age of 82 years.

Citing the GISAID genomic database, the study also found a slightly higher total of cases than the PHE ratio: two unrelated cases in Wales and a cluster of over a dozen in England, appearing from the first. fortnight of December 2020.

Vaccines more important 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’s a different story in places like South Africa, where many people had already been 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 spotted in the UK has now been found in at least 70 countries around the world, including around 470 known cases in the US, according to the US Centers for Disease Control and Prevention. United.

Experts say aggressive testing, adherence to COVID-19 guidelines, and rapid vaccine deployment are more important than ever in light of these variants of the spread.

“We need to get as many people vaccinated as possible as quickly as possible,” Fauci said. “Even if the protection against variants is diminished, the protection is sufficient to prevent you from contracting serious illnesses, including hospitalization and death.

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