* First tests of vaccine against new variants encouraging
* Scientists say mutations will need constant monitoring
* Variants found in South Africa, Britain more infectious
(Adds details, expert comment)
By Michael Erman
NEW YORK, Jan 7 (Reuters) - Pfizer Inc and
BioNTech's COVID-19 vaccine appears able to protect
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Texas Medical Branch, which has not yet been peer-reviewed,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 is linked to greater transmissibility and there
had been concerns 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 some hope
as Britain and other countries try to tame the more infectious
variants which authorities believe are driving a surge in
infections that could overwhelm healthcare systems.
The 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."
Dormitzer said another mutation found in the South African
variant, called the E484K mutation, was also concerning.
CONSTANT MONITORING
The U.S. researchers plan to run similar tests to see
whether the vaccine protects against other mutations found in
the British and South African variants and hope to have 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.
Independent experts gave a cautious welcome to the Pfizer
study findings, but said the situation needs constant vigilance.
Paul Hunter, a professor in medicine at Britain's University
of East Anglia, said "the jury is still out on the impact of the
South African variant on vaccine efficacy."
Deborah Dunn-Walters, a professor of immunology at Surrey
University in Britain, said it was "reassuring" that Pfizer is
closely monitoring variants.
Ongoing testing will be needed, experts said, to allay
concerns about whether vaccines being given to millions of
people in the fight against the pandemic will protect them as
the virus mutates. COVID-19 has killed more than 1.8 million
people worldwide.
"The evidence is not conclusive but there is a lot to
indicate that the existing MRNA vaccines do cover the new
variants. That is the good news," Andreas Bergthaler, principal
investigator at the Research Center for Molecular Medicine of
the Austrian Academy of Sciences in Vienna.
TESTS AND TWEAKS
AstraZeneca, Moderna and CureVac
are also testing whether their shots will protect against the
fast-spreading coronavirus variants. They have said they expect
them to be effective, but have not said when study results will
be published.
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 COVID-19 vaccine and the one from
Moderna Inc, which use synthetic messenger RNA
technology, can be quickly adapted to address new mutations in
the coronavirus if necessary. Scientists have suggested the
changes could be made in as little as six weeks.
The variant is not the first of the pandemic to emerge and
Eleanor Riley, a professor of immunology and infectious disease
at the Edinburgh University, said similar studies would need to
be repeated as new mutations appear. "It may be necessary to
tweak the vaccine over time," she said.
(Additional reporting by Kate Kelland in London and Doug
Busvine in Berlin ; Writing by Josephine Mason; Editing by Bill
Berkrot, Edwina Gibbs and Timothy Heritage)