The European Union’s drug regulator says it has found a “possible link” between the AstraZeneca-Oxford coronavirus vaccine and a rare blood-clotting disorder, but the benefits of the shot and the potential health consequences of suffering from COVID-19 still outweigh any risks.
The European Medicines Agency (EMA) said it would place no new restrictions on using the vaccine in people 18 and over, in both a statement and a subsequent news conference on Wednesday.
The EMA said most of the cases reported have occurred in women under 60 within two weeks of vaccination. The agency said based on the currently available evidence, it was not able to identify specific risk factors.
“The reported cases of unusual blood clotting following vaccination with the AstraZeneca vaccine should be listed as possible side-effects of the vaccine,” said Emer Cooke, the agency’s executive director.
Experts reviewed several dozen cases that came mainly from Europe and the United Kingdom, where around 25 million people have received the AstraZeneca-Oxford vaccine.
At a news conference from Brussels, Cooke said “the risk of mortality from COVID is much greater than the risk of mortality from these side-effects.”
Britain adjusts vaccine advice
The head of Britain’s drug regulator echoed that sentiment, but said on Wednesday people under 30 will be offered another product due to a rare blood clot risk. The Pfizer-BioNTech and Moderna vaccines should be offered to people in that age group instead, the Medicines and Healthcare Products Regulatory Agency (MHRA) advised.
Dr. June Raine, the head of the MHRA, said the risk “remains extremely low” at “about four people in a million” who receive the shot.
Raine said that as of the end of March, there had been 79 reports, all after the first dose, out of approximately 20 million doses given within the U.K. Of the adverse reports, 51 came from women.
Raine said the British regulator had tracked 19 deaths among those reports, three of them in people under the age of 30. The regulator said the reports did not constitute proof that the inoculation had caused the clots.
Jonathan Van Tam, Britain’s deputy chief medical officer, characterized the new recommendation as a “course correction” not uncommon for the rollout of vaccines used in treating other illnesses.
“You can’t pick these kinds of things up until you’ve literally deployed tens of millions of vaccines,” he said.
According to reports in Britain, the majority of those under 30 have yet to be vaccinated.
Based on current information, a causal relationship between the vaccine and the occurrence of blood clots with low platelets is considered plausible but is not confirmed. Specialised studies are needed to fully understand the potential relationship between vaccination and possible risk factors.
Canada already recommended shot for those 55 and over
Canada approved AstraZeneca-Oxford doses being manufactured in both Europe and in India, where it has been branded as Covishield. The vaccine first arrived in Canada in early March, and later in the month, Ottawa announced it had received a loan from the United States of 1.5 million additional doses, as a hearing on the vaccine’s approval has yet to be held by American regulators.
Canada’s National Advisory Committee on Immunization (NACI) updated its recommendations in late March regarding the use of the AstraZeneca-Oxford vaccine in light of the blood clot reports seen in Europe. The committee recommended a pause in inoculating Canadians under 55 with that vaccine.
In its tracking of potential adverse events following vaccination, Health Canada has received no reports of the rare blood clotting in this country.
WATCH | Canada’s vaccine advisory committee adjusts AstraZeneca guidelines:
Dr. Shelley Deeks, co-chair of NACI, said at a virtual briefing on Tuesday that Canadian officials will study the updated data from their European counterparts to see if any advice needs to be updated. She said it would be “premature” to say if the latest development in Europe will have any effect on confidence in the AstraZeneca-Oxford vaccine.
“What we’ve tried to be doing at NACI is actually being quite transparent about the evolution of the data so Canadians will have confidence that we are communicating what we know about safety, when we know it,” said Deeks.
The EMA is particularly focused on two types of rare blood clots: one that appears in multiple blood vessels and another that occurs in a vein that drains blood from the brain. It also evaluated reports of people who had low levels of blood platelets, which puts them at risk of severe bleeding.
Raine said 14 of the 19 fatalities noted were cases where cerebral venous sinus thrombosis with low platelets was present, while the other cases were associated with other kinds of thrombosis in major veins.
As recently as last week, the EMA said “there is no evidence that would support restricting the use of this vaccine in any population” — a response to several countries doing just that — though an expert said more brain clots were being reported than would be expected.
In March, more than a dozen countries, mostly in Europe, suspended their use of AstraZeneca-Oxford over the blood clot issue. Most restarted — some with age restrictions — after the EMA said countries should continue using the potentially life-saving vaccine.
WATCH European Union regultator says blood clot risk extremely rare:
The suspensions were seen as particularly damaging for AstraZeneca because they came after repeated missteps in how the company reported data on the vaccine’s effectiveness and concerns over how well its shot worked in older people.
Cooke characterized the reports as evidence that caution and transparency have been guiding decisions.
“These very rare and unusual events were picked up, identified, analyzed and we have made a clear science-based recommendation to allow the safe and effective use of the vaccine,” she said.
Dr. Peter English, who formerly chaired the British Medical Association’s public health medicine committee, said the back-and-forth over the AstraZeneca vaccine globally could have serious consequences.
“We can’t afford not to use this vaccine if we are going to end the pandemic,” he said.
That’s because the vaccine is cheaper and easier to store than many others, is critical to Europe’s immunization campaign and a pillar of the United Nations-backed program known as COVAX that aims to get vaccines to some of the world’s poorest countries.
On Tuesday, AstraZeneca and Oxford University paused a study of the shot in children while the U.K. regulator evaluates the link between the shot and rare blood clots in adults.