Analysis-World watches as first-mover Britain probes adverse reactions
to Pfizer vaccine
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[December 11, 2020]
By Alistair Smout
LONDON (Reuters) - Britain hailed "V-Day"
when it became the first country to roll out the Pfizer-BioNTech
COVID-19 vaccine. Yet, as first mover, it has also become the first to
report cases of adverse reactions, allowing other nations to watch and
learn.
Officials from around the world are keen for British authorities to give
them as much information as possible about the two reported cases of
anaphylaxis among thousands of people inoculated since mass-vaccination
began on Tuesday.
Anaphylaxis is an over-reaction of the body's immune system, which
health specialists describe as severe and sometimes life-threatening.
While such allergic reactions are rare in any individual vaccine
recipient, they are not unusual during large-scale rollouts, scientists,
experts and industry figures said.
The reports nonetheless led to Britain's Medicines and Healthcare
products Regulatory Agency (MHRA) beefing up its guidance for the shot
at midnight leading into Thursday, specifically warning that anyone with
a history of anaphylaxis should not take it.
In the United States, regulators and public health officials are
determining whether to approve the vaccine from Pfizer and BioNTech, and
what advice to issue.
William Schaffner, an infectious disease expert at Vanderbilt University
Medical Center, said the British regulator was being cautious in its
approach to the shot, which uses new genetic mRNA technology.
"They're being very, very careful. These are new vaccines using a new
technology. They've gotten a signal here that they need to investigate,"
he said.
"We'll benefit from their investigation."
Schaffner, who is a non-voting member of Centers for Disease Control and
Prevention's Advisory Committee on Immunization Practices, said the
group would likely discuss the topic when it discusses the use of
Pfizer's vaccine on Friday.
Stephen Hahn, commissioner of the U.S. Food and Drug Administration,
said his agency was trying to learn from the UK experience.
"We're working very closely with our UK partners to understand what went
on with respect to those allergic reactions," he told CBS News ahead of
a meeting of outside advisers to weigh whether to recommend approval of
the vaccine.
Canada's health ministry, which approved the vaccine on Wednesday, also
said it would look at the reported reactions in Britain, but added that
adverse events were to be expected and would not necessarily change the
risk/benefit of the shot.
'BENEFITS OUTWEIGH RISKS'
The MHRA, which last week became the first regulator in the world to
approve the vaccine, said it was looking into the reports of anaphylaxis
as a matter of priority.
"Anaphylaxis is a known, although very rare, side effect with any
vaccine," the watchdog said. "Most people will not get anaphylaxis and
the benefits in protecting people against COVID-19 outweigh the risks."
Its updated guidance to health professionals reads: "Any person with a
history of anaphylaxis to a vaccine, medicine or food should not receive
the Pfizer-BioNTech vaccine."
That fleshed out an earlier change, in response to the reports of
adverse reactions, that had more broadly warned against those with a
history of a "significant allergic reaction" to a vaccine, medicine or
food taking the shot.
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A nurse holds a vial of the Pfizer/BioNTech COVID-19 vaccine at
University Hospital, on the first day of the largest immunization
program in the British history, in Coventry, Britain December 8,
2020. Jacob King/Pool via REUTERS
A vaccination resources database for doctors in France estimates the
number of anaphylaxis events at below 1 per 100,000 doses, although
it says it can happen to "any patient with any type of vaccines".
Paul Turner, an expert in allergy and immunology at Imperial College
London's who has been advising the MHRA, said it was unlikely the
adverse reactions were due to food allergies.
They may have been caused by a component of Pfizer's vaccine called
polyethylene glycol, or PEG, which helps stabilise the shot and is
not in other types of vaccines, he added.
"As we've had more information through, the initial concern that
maybe it affects everyone with allergies is not true," he said.
"Likewise, people with a known allergy to just one medicine should
not be at risk," Turner told Reuters.
Pfizer and BioNTech said they were supporting the MHRA
investigation.
Pfizer has said people with a history of severe adverse allergic
reactions to vaccines or the candidate's ingredients were excluded
from their late-stage trials, which is reflected in the MHRA's
emergency-approval protocol.
'CAN GET A HANDLE ON IT'
The British regulator insisted no corners were cut when it issued
emergency use approval for Pfizer's vaccine last Wednesday, adding
that the highest standards were maintained, despite raising some
eyebrows abroad with the move.
Top U.S. infectious diseases expert Anthony Fauci apologised for
casting doubt on the MHRA's rigour last week, while the EU drug
regulator has said its process was more appropriate for the
pandemic.
The founder of German biotech firm CureVac, whose own COVID-19
vaccine based on mRNA technology is in clinical trials, said the
side effects seen in Britain were unsurprising.
"It is quite clear, with the immune system, that this can also
explode. This applies to all immunisations, including the flu
vaccination, for example," Ingmar Hoerr told RTL/ntv.
"But that's not so bad, you can get a handle on it. You can take
medication that brings the immune system down again."
(Reporting by Alistair Smout; Additional reporting by Matthias
Blamont in Paris, Caroline Copley in Berlin, Julie Steenhuysen in
Chicago and Francesco Guarascio in Brussels; Editing by Pravin Char)
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