Syringes are filled with Astrazeneca’s vaccine in the pharmacy.
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LONDON – Europe’s drug regulator has identified a possible link between the coronavirus vaccine developed by and AstraZeneca and Oxford University and rare blood clotting problems – though the benefits of the shot still outweigh the risks.
Unusual clotting with low platelets is added to the vaccine product information as a “very rare” side effect, along with a number of other possible side effects, said Emer Cooke, executive director of the European Medicines Agency, in a television press conference Wednesday.
The warning comes after the regulator’s safety committee reviewed extremely rare cases of unusual blood clots in some people vaccinated with the Oxford-AstraZeneca shot. Most cases occurred in women under 60 within two weeks of the shot. The EMA has not yet identified any specific risk factors that contributed to this phenomenon.
The researchers also don’t know what specifically causes the clots, but one plausible explanation is that the vaccine elicits an immune response in some people similar to that seen in patients treated with heparin, known as heparin-induced thrombocytopenia, said Cooke.
“This case clearly shows one of the challenges posed by large-scale vaccination campaigns,” she said. “When millions of people receive these vaccines, very rare events that have not been identified in clinical trials can occur.”
Separately, the UK Medicines Agency announced on Wednesday that it had also identified a possible link between the shot and the rare blood clots. The Medicines and Health Products Regulator (MHRA) also said the benefits of Oxford-AstraZeneca’s vaccine outweighed the risks for most people.
The UK’s Joint Committee on Vaccination and Immunization said people under the age of 30 who have no health problems should get a different vaccine if possible.
The EMA highlighted other possible side effects, adding that it was “of great importance” that health professionals and those receiving the Oxford-AstraZeneca vaccine are aware of the risks and watch out for possible symptoms that are typical occur in the first two weeks after inoculation.
“These include, for example, shortness of breath, chest pain, swelling in the leg, persistent abdominal pain, neurological symptoms such as severe or persistent headaches or blurred vision and skin bruises beyond the injection site,” said Dr. Sabine Straus, chair of EMA’s security committee, said at the same press conference. These side effects are listed in the vaccine’s product information as possible adverse drug reactions, she said.
AstraZeneca’s shares closed around 1% in London.
Professor Jonathan Van-Tam, the UK’s Deputy Chief Medical Officer, described the country’s new Oxford-AstraZeneca vaccine council as a “course correction” for the UK.
The MHRA, the body that approved it for use in the UK, examined the data following reports – in both the UK and continental Europe – of serious but rare blood clots, some of which were fatal.
A UK study of the Oxford AstraZeneca vaccine in children has already been paused while the drug agency investigated a possible link between the shot and the bleeding disorders, particularly cases of blood clots in veins in the brain known as cerebral venous sinus thrombosis (CVST) as well Thrombocytopenia (low blood platelet levels that help blood to clot).
The UK government noted that as of March 24th inclusive, there were 22 reports of CVST and 8 reports of other low platelet thrombosis events totaling 18.1 million doses of the AstraZeneca vaccine (one shot with two doses). given up to this date.
The Oxford-AstraZeneca shot has been followed by security concerns in several European countries in recent weeks briefly suspend their use of the vaccine in the past month.
The EMA said on March 31 that it had found the shot safe and effective but added that it could not rule out the possibility of a causal link between the vaccine and clotting events, it would therefore investigate further.
The World Health Organization, the United Kingdom Medicines Agency and the International Society for Thrombosis and Hemostasis Everyone has said the benefits of administering the Oxford-AstraZeneca shot far outweigh the risks.
People are waiting in a vaccination center in Cologne on April 5, 2021.
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AstraZeneca previously said that its studies didn’t find a higher risk of blood clots as a result of its vaccine.
Most countries have since resumed the use of the shot, but many have suspended vaccinations for certain age groups.
The EMA had denied any known link between the Oxford-AstraZeneca shot and rare blood clots before Tuesday, as a senior official with the European Medicines Agency According to reports said there is a clear “association” between the Oxford-AstraZeneca vaccine and very rare blood clots in the brain.
In an interview with the Italian newspaper Il Messaggero published on Tuesday, Marco Cavaleri, chairman of the EMA’s vaccine evaluation team, said: “In my opinion, we can now say that there is a link to the vaccine, but we are still me don’t know what is causing this reaction. “
– CNBC’s Holly Ellyatt contributed to this report.