* EMA says review of AstraZeneca vaccine is ongoing
* Review findings expected on Wednesday or Thursday - EMA
* France, Germany, Netherlands, suspend AZ in younger people
* Another EMA committee member says link "plausible"
(Edits, adds expert comment)
ROME, April 6 (Reuters) - A senior official at Europe's
medicines regulator has said there is a clear "association"
between AstraZeneca's COVID-19 vaccine and very rare
blood clots in the brain, though the direct cause of the clots
is still unknown.
The European Medical Agency (EMA) said in a statement after
the comments by Marco Cavaleri, chair of its vaccine evaluation
team, that it was still conducting a review of the vaccine and
expected to announce its findings on Wednesday or Thursday.
An AstraZeneca spokesman declined to comment on Cavaleri's
remarks, which he made in an interview with Italian newspaper Il
Messagero that was published on Tuesday.
"In my opinion, we can now say it, it is clear that there is
an association (of the brain blood clots) with the vaccine.
However, we still do not know what causes this reaction,"
Cavaleri said, without giving evidence to support his comments.
The EMA has said the benefits of the AstraZeneca shot
outweigh any risks, and the World Health Organization has backed
the vaccine. AstraZeneca has said previously that its studies
have found no higher risk of clots because of its vaccine.
The EMA is investigating 44 reports of an extremely rare
brain clot known as cerebral venous sinus thrombosis (CVST) out
of 9.2 million people who have received the vaccine in the
European Economic Area, which comprises European Union member
states and Iceland, Liechtenstein and Norway.
Cavaleri said the EMA would say in its review that there is
a link, but was not likely to give an indication this week on
which age groups should or should not get the AstraZeneca shot.
Some countries, including France, Germany and the
Netherlands, have suspended the use of the vaccine in younger
people while the investigations continue.
REVIEW ONGOING
In response to Cavaleri's comments, the Amsterdam-based EMA
said in a statement on Tuesday: "EMA’s Pharmacovigilance Risk
Assessment Committee (PRAC) has not yet reached a conclusion and
the review (of any possible link) is currently ongoing."
The EMA said last week that its review had not identified
any specific risk factors, such as age, gender or medical
history, for these very rare events.
In a separate interview, Armando Genazzani, a member of the
EMA's Committee for Medicinal Products for Human Use (CHMP),
told La Stampa daily that it was "plausible" that the blood
clots were correlated with the AstraZeneca vaccine.
A high proportion of the reported cases are in young or
middle-aged women, but that has not led the EMA to conclude this
group is at particular risk.
Scientists are exploring several possibilities that might
explain the rare brain blood clots.
One theory suggests the vaccine triggers an unusual antibody
in some rare cases; other investigators are looking into a
possible link with birth control pills.
But many experts say there is no definitive evidence and it
is not clear whether or why AstraZeneca's vaccine would cause a
problem not shared by other vaccines that target a similar part
of the coronavirus.
"We need to know more about the people affected and we need
to understand exactly how the illnesses came about, while many
other questions remain unanswered at this time," said Adam Finn,
a professor of paediatrics at Britain's Bristol University who
has been involved with UK studies of several COVID-19 vaccines,
including the AstraZeneca shot and another developed by Pfizer.
He said it was very clear that clotting cases were "very
rare indeed" and that the vaccines that are available and in use
in Britain "prevent COVID very effectively".
(Reporting by Giulia Segreti; Additonal reporting by Kate
Kelland in London, and Toby Sterling and Anthony Deutsch in
Amsterdam; Editing by Giles Elgood, Gareth Jones and Timothy
Heritage)