LONDON (Reuters) – European and British regulators said on Wednesday they had found possible links between AstraZeneca’s vaccine and very rare cases of blood clots, but confirmed its importance in protecting people from COVID-19.
A British government advisory group said the vaccine should not be given to under-30s where possible, although an official said this was “really out of the utmost caution, rather than because we have serious safety concerns”
More than a dozen countries have at one time suspended the use of the vaccine, which has been given to tens of thousands of millions in Europe. But most have resumed, and some, including France, the Netherlands and Germany, have set a minimum age.
Now, rising infections caused by more contagious variants are threatening to overwhelm hospitals in many EU countries – where the rate of vaccination is far behind the UK and US – forcing France and others to reintroduce social and economic lockdown.
The European Medicines Agency (EMA) received reports of 169 cases of the rare cerebral blood clot in early April, after 34 million doses had been administered in the European Economic Area, according to Sabine Straus, chair of the EMA’s safety committee. The EEA includes the 27 EU countries plus Iceland, Norway and Liechtenstein.
In comparison, four women out of 10,000 would get blood clots by taking oral contraceptives.
In its statement, the EMA said it reminded healthcare professionals and recipients to remain aware of “the possibility of very rare cases of blood clots combined with low levels of platelets occurring within 2 weeks of vaccination”.
NO NEW GUIDELINES
“So far, most of the reported cases have occurred in women under 60 within 2 weeks of vaccination,” it added. However, it did not issue any new guidelines.
Professor Frederic Adnet, head of emergency services at Avicenne Hospital in Bobigny, France, said the statement would nonetheless affect admission in France, where skepticism about vaccines is high.
“EMA’s communication today will undoubtedly further affect confidence in AstraZeneca’s vaccine,” he said.
EU health ministers began meeting shortly after the EMA’s declaration.
AstraZeneca’s shots are sold at cost of a few dollars a dose. It is by far the cheapest and largest volume launched to date and has none of the extreme cooling requirements of some other COVID-19 vaccines.
After extensive use in the UK and mainland Europe, it is set to be the cornerstone of vaccination programs in large parts of developing countries.
The World Health Organization’s advisory panel on vaccines said a causal link with low platelet counts “is considered probable but not confirmed”.
Experts say that although a causal link has been proven, the risk to the general population of getting a severe blood clot is negligible compared to the risk of possible COVID-19 infection, which can also cause similar blood clots or from many other widely used drugs such as p -pills.
“The risk of mortality due to COVID is much greater than the risk of mortality due to these rare side effects,” said EMA CEO Emer Cooke.
BENEFITS BALANCED RISK
Nevertheless, AstraZeneca’s shares fell 1.2% at a 2-week low.
But the shot has been in question since the end of last year, when the drugmaker and Oxford University released experimental data with two different efficacy measurements as a result of a dosing error.
The company last month released early results from its late-year U.S. clinical trial that showed the shot was 79% effective, but then had to fight to release more data after a rare reprimand from U.S. health officials that said the data was outdated. .
The head of the UK’s drug regulator, June Raine, said the benefits outweighed the risks for the vast majority, but were more balanced for younger people – for whom the risk of coronavirus infection is lower on average.
Wei Shen Lim, COVID-19 chair of the UK Advisory Committee on Vaccines and Immunization, said it was preferable that adults under the age of 30 without underlying health conditions be offered another vaccine.
AstraZeneca has said that its own studies have not found any higher risk of blood clots in the vaccinated than in the general population.
Researchers are exploring several possible causes of the rare cerebral sinus blood clots. One theory suggests that in rare cases, the vaccine triggers an unusual antibody; other investigators are looking at a possible connection with birth control pills.
But there is no definitive evidence yet, and many experts say it is not clear if or why AstraZeneca’s vaccine would cause a problem not shared by other vaccines targeted at a similar part of the virus.
Reporting by Francesco Guarascio, Kate Kelland, Alistair Smout, John Miller, Toby Sterling, Bart Meijer, Anthony Deutsch, Pushkala Aripaka, Stephane Nebehay, and Josephine Mason; Writing by Nick Macfie; Edited by Kevin Liffey