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(Adds details from briefing)
By David Ljunggren and Allison Martell
OTTAWA/TORONTO, March 29 (Reuters) - Canadian health
officials said on Monday they would stop offering AstraZeneca's
COVID-19 vaccine to people under age 55 and require a
new analysis of the shot's benefits and risks based on age and
gender.
The moves follow reports from Europe of rare but serious
blood clots, bleeding and in some cases death after vaccination,
mainly in young women. No such cases have been reported in
Canada, with about 307,000 AstraZeneca doses administered.
"We are pausing the use of AstraZeneca vaccine to adults
under 55 years of age pending further risk benefit analysis,"
Canada's deputy chief public health officer Howard Njoo said at
a media briefing.
Njoo later noted that Canada was taking this "prudent"
approach because alternative vaccines are available. Most of
Canada's supply so far has come from Pfizer Inc and
Moderna Inc.
The National Advisory Council of Immunization (NACI), an
independent expert panel, said the rate that the clotting
complication happens at is not yet clear. So far, 40% of people
who have developed it have died, but that may fall as more cases
are identified and treated early, it said.
"From what is known at this time, there is substantial
uncertainty about the benefit of providing AstraZeneca COVID-19
vaccine to adults under 55 years of age," the council in a
written recommendation.
Older people face a greater risk of hospitalization and
death from COVID-19, and the complication seems to be more rare
in that age group, NACI said, so they can be offered the vaccine
"with informed consent."
Health Canada said in a statement it would add new terms and
conditions to the vaccine's authorizations, including "a
requirement that the manufacturers conduct a detailed assessment
of the benefits and risks of the vaccine by age and sex in the
Canadian context."
Health Canada said it had been in talks with AstraZeneca,
and once it has the requested information, it "will determine if
additional regulatory actions are necessary."
It was not immediately clear how long the assessment might
take.
The pause affects both versions of the vaccine approved in
Canada: One granted to AstraZeneca Canada, and a second for the
Serum Institute of India (SII) - which is manufacturing its own
version of the vaccine under license - and its Canadian partner
Verity Pharmaceuticals.
Many European countries briefly stopped using the
Anglo-Swedish firm's vaccine while investigating the blood clot
incidents earlier this month. Canada continued to administer
doses, arguing that the benefits of vaccination outweighed
potential risks.
Nearly all countries have since resumed use of the
AstraZeneca vaccine. But France broke with guidance from the
European medical regulator and said on March 19 it should only
be given to people aged 55 or older. France said the decision
was based on evidence that the clotting affected younger people.
Canada is expecting another 1.5 million doses of the
AstraZeneca vaccine this week from the United States, which has
not yet authorized its use. Canada has ordered more than 20
million doses from AstraZeneca and SII.
(Reporting by David Ljunggren and Steve Scherer in Ottawa;
writing by Allison Martell in Toronto
Editing by Paul Simao and Bill Berkrot)
