Canada Urges Halt in Use of AstraZeneca Covid-19 Vaccine in People Under 55 -- Update
March 29 2021 - 6:31PM
Dow Jones News
By Paul Vieira and Kim Mackrael
OTTAWA -- Canadian authorities recommended Monday a halt on
administering the AstraZeneca PLC Covid-19 vaccine on people under
the age of 55 in light of evidence from Europe on potentially
serious side effects targeting younger women.
The change in guidance marked a sharp shift from Canadian health
officials, who up until now have said the AstraZeneca vaccine was
safe for people of all ages -- a point they emphasized earlier this
month when governments in Europe paused the vaccine's use amid
worries over blood clotting. This also marks the latest setback for
the British-Swedish drugmaker, which has faced pushback from
governments, regulators and the public about the rollout of its
vaccine.
Health Canada, the country's drug regulator, has ordered
AstraZeneca to conduct a detailed risk-benefit analysis on the
vaccine by age and gender. The information, officials said, would
help determine whether specific demographic groups might be at
higher risk.
Canadian officials said the change in guidance on AstraZeneca
stems from the emergence of additional reports of blood clotting in
people who received the vaccine in Europe. Some European cases were
reviewed in a recent preprint research paper that focused on nine
patients in Germany and Austria. The findings from the preprint
were first reported by researchers earlier this month.
The preprint research looked at nine patients whose ages ranged
from 22 to 49 and who had developed thrombosis, which occurs when a
blood clot forms inside a blood vessel, beginning four to 16 days
after getting the AstraZeneca vaccine. Eight of the patients were
female. Four of the nine patients died.
The paper refers to blood clotting after a Covid-19 vaccination
as a rare adverse effect, and one that has so far only been
reported in patients who received the AstraZeneca vaccine.
Canadian officials said that, based on information from Europe,
the incident rate was originally estimated at one per one million
people vaccinated with the AstraZeneca vaccine, but a higher rate
of one in 100,000 was later reported by researchers in Germany.
Among the people who developed blood clotting after receiving the
vaccine, the fatality rate is estimated at 40%, the officials
said.
Considering this information and knowing that Canada has
authorized three other Covid-19 vaccines, "there is substantial
uncertainty about the benefit of providing AstraZeneca Covid-19
vaccine to adults under 55 years of age given the potential risk,"
said Dr. Shelley Deeks, vice chairwoman of the National Advisory
Committee on Immunization, an independent panel of scientists.
The panel's recommendations aren't binding. At least two
Canadian provinces, which are responsible for carrying out Covid-19
vaccinations, said they were immediately halting use of the
AstraZeneca shot on younger people.
"This is a pause while we wait for more information to better
understand what we are seeing in Europe," said Dr. Joss Reimer,
head of Manitoba's vaccine task force. "We have to respond to what
we know, when we know it, in this vaccine campaign."
An AstraZeneca spokesman said the company respects the decision
from the immunization advisory panel. He added that Health Canada
still deems the vaccine safe for use, and an "extensive body of
data from two large clinical data sets and real-world evidence
demonstrate its effectiveness, reaffirming the role the vaccine can
play during this public health crisis."
Canada authorized use of the AstraZeneca vaccine, created in
partnership with the University of Oxford, on Feb. 26. Health
Canada -- which has oversight on drugs -- has said the benefits of
the vaccine outweighed any risks and stuck to that position while
European countries paused AstraZeneca's use because of concerns
about the risk of blood clotting in older people. The European
Union's health agency later determined the shot was safe and
effective and didn't increase the risk of blood clots.
Dr. Supriya Sharma, senior medical adviser at the country's
health department, said last week that reports of blood clots after
vaccination were rare, but their unusual nature warranted further
investigation. She said Health Canada would review evidence about
the blood clots as it becomes available and would take action if
new safety issues are confirmed.
On Monday, Dr. Sharma said she supported the recommendation,
while adding that the AstraZeneca vaccine will still remain
effective in preventing hospitalizations and deaths for people 55
and over, or those most susceptible to Covid-19's fallout. "It's
reasonable to pause for a period of time while this [risk]
continues to be evaluated," she said. "I fully understand this can
be confusing. Especially for this vaccine, which has had a lot of
confusion surrounding it."
To date, officials said about 300,000 Canadians have received a
shot of the AstraZeneca vaccine. Canada authorized use of
AstraZeneca's shot in late February, whereas in the U.S. the
vaccine remains under review. It is rare for Health Canada to get
so out in front of the Food and Drug Administration on drug
authorization, said Mark Warner, a lawyer who practices in Canada
and the U.S. who has advised pharmaceutical companies.
"That choice and the continuing noise around the AstraZeneca
vaccine has led to some predictable confusion in the rollout of the
vaccine in Canada," he said.
Write to Paul Vieira at paul.vieira@wsj.com and Kim Mackrael at
kim.mackrael@wsj.com
(END) Dow Jones Newswires
March 29, 2021 18:16 ET (22:16 GMT)
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