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* UK says worried about S.African variant
* Mutations include extensive alterations to spike protein
* Changes could lead to "escape from immune protection"
* Vaccine makers are testing shots against new variants
(Recasts with quotes, details from scientists)
LONDON, Jan 4 (Reuters) - UK scientists expressed concern on
Monday that COVID-19 vaccines being rolled out in Britain may
not be able to protect against a new variant of the coronavirus
that emerged in South Africa and has spread internationally.
Both Britain and South Africa have detected new, more
transmissible variants of the COVID-19-causing virus in recent
weeks that have driven a surge in cases. British Health
Secretary Matt Hancock said on Monday he was now very worried
about the variant identified in South Africa.
Simon Clarke, an associate professor in cellular
microbiology at the University of Reading, said that while both
variants had some new features in common, the one found in South
Africa "has a number additional mutations ... which are
concerning".
He said these included more extensive alterations to a key
part of the virus known as the spike protein - which the virus
uses to infect human cells - and "may make the virus less
susceptible to the immune response triggered by the vaccines".
Lawrence Young, a virologist and professor of molecular
oncology at Warwick University, also noted that the South
African variant has "multiple spike mutations".
"The accumulation of more spike mutations in the South
African variant are more of a concern and could lead to some
escape from immune protection," he said.
Scientists including BioNTech CEO Ugur Sahin and John Bell,
Regius Professor of Medicine at the University of Oxford, have
said they are testing the vaccines against the new variants and
say they could make any required tweaks in around six weeks.
Public Health England said there was currently no evidence
to suggest COVID-19 vaccines would not protect against the
mutated virus variants. Britain's health ministry did not
immediately respond to requests for comment.
The world's richest countries have started vaccinating their
populations to safeguard against a disease that has killed 1.8
million people and crushed the global economy.
There are currently 60 vaccine candidates in trials,
including those already being rolled out from AstraZeneca
and Oxford, Pfizer and BioNTech,
Moderna, Russia's Sputnik V and China's Sinopharm
.
Scientists say both the South African and UK variants are
associated with a higher viral load, meaning a greater
concentration of virus particles in patients' bodies, possibly
contributing to increased transmission.
Oxford's Bell, who advises the UK government's vaccine task
force, said on Sunday he thought vaccines would work on the
British variant but said there was a "big question mark" as to
whether they would work on the South African variant.
BioNTech's Sahin told Germany' Spiegel in an interview
published on Friday that their vaccine, which uses messenger RNA
to instruct the human immune system to fight the virus, should
be able to protect against the UK variant.
"We are testing whether our vaccine can also neutralise this
variant and will soon know more," he said.
(Reporting by Kate Holton, Kate Kelland, Guy Faulconbridge and
Alistair Smout; Editing by Mike Collett-White)
