Pfizer-BioNTech vaccine appears effective against mutation in new coronavirus variants, study suggests
First results of tests on new variants encouraging, more studies needed
Pfizer Inc. and BioNTech's COVID-19 vaccine appeared to work against a key mutation in the highly transmissible new variants of the coronavirus discovered in Britain and South Africa, according to a laboratory study conducted by the U.S. drugmaker.
The study by Pfizer and scientists from the University of Texas Medical Branch, which has not yet been peer-reviewed, indicated the vaccine was effective in neutralizing virus with the so-called N501Y mutation of the spike protein.
The mutation could be responsible for greater transmissibility and there had been concern it could also make the virus escape antibody neutralization elicited by the vaccine, said Phil Dormitzer, one of Pfizer's top viral vaccine scientists.
The first results of tests on the variants offer a glimmer of hope while more studies are carried out as Britain and other countries try to tame the more infectious variants that authorities believe are driving a surge in infections that could overwhelm health-care systems.
The Pfizer-BioNTech study was conducted on blood taken from people who had been given the vaccine. Its findings are limited because it does not look at the full set of mutations found in either of the new variants of the rapidly spreading virus.
Dormitzer said it was encouraging that the vaccine appears effective against the mutation, as well as 15 other mutations the company has previously tested against.
"So we've now tested 16 different mutations, and none of them have really had any significant impact. That's the good news," he said. "That doesn't mean that the 17th won't."
WATCH | What scientists know about the new coronavirus variant:
Dormitzer said another mutation found in the South African variant, called the E484K mutation, was also concerning.
The researchers plan to run similar tests to establish whether the vaccine is effective against other mutations found in the British and South African variants and hope to have more data within weeks.
The variants are said by scientists to be more transmissible than previously dominant ones, but they are not thought to cause more serious illness.
The virus's spikes act as a key that must unlock our cells to cause the infection. The variant first identified in the U.K. has a mutation that appears to make it easier for the coronavirus to grab hold of the lock more tightly, scientists say.
Scientists said the results of the study would help calm concerns that people will not be protected by vaccines being given to millions of people around the world in the fight against the pandemic, which has killed more than 1.8 million people and roiled economies.
But they cautioned that more clinical tests and data are still needed to come to a definitive conclusion.
"This is good news, mainly because it is not bad news," said Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine.
"So, yes this is good news, but it does not yet give us total confidence that the Pfizer (or other) vaccines will definitely give protection."
AstraZeneca, Moderna, CureVac testing against variants
AstraZeneca, Moderna and CureVac are also testing whether their shots work against the fast-spreading variants. They have said they expect them to be effective, but the timing of those studies is not known.
A senior British lawmaker expressed concerns in an interview on Friday that COVID-19 vaccines might not work properly against the South African variant. He was not responding to questions about Friday's data.
The Pfizer-BioNTech vaccine and the one from Moderna Inc., which use synthetic messenger RNA technology, can be quickly tweaked to address new mutations of a virus if necessary. Scientists have suggested the changes could be made in as little as six weeks.
Some other vaccines to protect against COVID-19 also use the spike protein to show our immune system what the enemy looks like.
Canadian microbiologist Benjamin tenOever, a professor at the Icahn School of Medicine at Mount Sinai in New York, said our immune system learns to recognize and attack the viral attachment protein at many different sites.
"It would require many many mutations to render our vaccines non-effective," tenOever said.
The variant is also not the first of the pandemic to emerge and Eleanor Riley, professor of immunology and infectious disease at the University of Edinburgh, said these types of studies will be needed as they appear.
"It may be necessary to tweak the vaccine over time," she said.
Dr. Theresa Tam, Canada's chief public health officer, said Friday that 14 cases of the variant first reported in the U.K. have been reported in Canada.
Researchers in Ontario have developed a faster test to identify variants.
With files from CBC's Christine Birak
