AstraZeneca’s Vaccine Faces Blood Clot Concerns
Germany, France, Italy and Spain stopped all vaccinations with the AstraZeneca COVID-19 vaccine, following reports of rare blood clots in people who received the shots.
These moves by the four largest countries in the European Union are pausing in several smaller Member States – and signal a new crisis of confidence in an affordable vaccine seen as the best hope for accelerating COVID-19 vaccination in the developing world.
Experts point out that there is still no clear evidence that the vaccine causes these reported clots and that the cases are being investigated by regulators. However, the latest concerns follow previous questions from scientists about how the company has reported issues regarding the safety and efficacy of its vaccine. It also comes shortly before AstraZeneca is expected to release results from a large-scale clinical trial that will determine if the FDA approves the vaccine for use in the United States.
Vaccination delays in Europe were triggered by reports of three hospitalizations, including one patient who died, among those who received the vaccine in Norway, and one further death in Denmark. In a statement issued on March 11, the European Medicines Agency – the regulator equivalent to the EU FDA – said there were a total of 30 cases of “thromboembolic events” or blood clots among the 5 million people who took AstraZeneca plans in EU.
“There is currently no indication that the vaccine has caused these conditions, which are not reported as side effects with this vaccine,” the EMA said. “The position of the EMA ασφά safety committee is that the benefits of the vaccine continue to outweigh the risks associated with it and the vaccine may continue to be administered.”
AstraZeneca said there were a total of 37 reported cases of pulmonary embolism and deep vein thrombosis, both of which were caused by blood clotting, which is lower than expected by the general population.
“About 17 million people in the EU and the UK have received our vaccine and the number of blood clots reported in this group is lower than the hundreds expected,” said Ann Taylor, chief medical officer. issued March 14.
And the World Health Organization is urging countries to continue using the vaccine, reiterating that there is no evidence that it causes blood clots. WHO experts meet to discuss blood clot reports Tuesday.
However, a few incidents cause some countries to pause. According to German Health Minister Jens Spahn, seven cases of rare disease, cerebral venous thrombosis (CSVT), have been reported out of the 1.6 million people who received the AstraZeneca vaccine in Germany. The Paul Ehrlich Institute, a member of the German Ministry of Health, said on Monday that it was concerned that the condition was reported along with unusual bleeding and low platelet counts, which form clots and prevent bleeding.
The handful of cases observed in Germany so far would be more than expected, but it could be a statistical upheaval. «[T]”The likelihood of such a statistical clustering for an outcome is actually quite high even when there is no cause and effect,” said Paul Hunter, a public health specialist at the University of East Anglia, in a comment distributed through his Science Media Center. United Kingdom.
The EMA is meeting to discuss blood clotting concerns on Tuesday and is expected to release its findings on Thursday. A prolonged gap in vaccination would be a worrying prospect, as COVID-19 cases are rising again in many EU nations – with Italy experiencing a particularly worrying increase – as more contagious variants spread.
Experts who contacted BuzzFeed News said that, without knowing more about the patients’ cases, there was not enough evidence to draw clear conclusions about whether the vaccine caused coagulation. “We would like to know the age of the cases, their previous medical history and conditions that could predispose them to either a blood clot or bleeding,” said Orly Vardeny of the University of Minnesota, a pharmacologist who specializes in heart health.
“It may or may not be related to the vaccine. “If it ‘s related to the vaccine and it does not appear everywhere, the most likely explanation would be a batch issue,” John Moore, a virologist at Weill Cornell Medical College in New York, told BuzzFeed News. (Some countries, including Austria, have specifically stopped vaccination against certain batches of AstraZeneca.)
The new concerns are the latest in a string of obstacles to AstraZeneca COVID-19 vaccine being developed at the University of Oxford. In November, AstraZeneca claimed in a press release that the vaccine was 70% effective overall and could be up to 90% effective if given at half dose for the first of two doses. But many scientists were skeptical, especially after the drug company admitted that the regimen was the result of a miscalculation. AstraZeneca later added to the confusion by changing its explanation for the claimed efficacy of 90% from the dose itself to the delay between the two doses.
A more serious blow came in February, when tests in South Africa showed that the vaccine was not effective against the most contagious variant of the coronavirus circulating there. South Africa abruptly discontinued AstraZeneca vaccine plans and switched to vaccines developed by Johnson & Johnson and Pfizer / BioNTech.
Scientists are now awaiting the results of a major test of the AstraZeneca vaccine in the United States and other countries that will be the cornerstone of the company’s FDA approval of the vaccine for use. However, some experts wonder whether the addition of AstraZeneca to the arsenal of vaccines used in the US will create more problems, with anti-criminals taking advantage of the negative publicity surrounding it to undermine the wider vaccination effort.
“Does he really have a place to fill? Would it be reliable enough? Or will it just be another headache? said Moore.
Child Health’s Defense, an organization that has delivered years of misinformation and conspiracy theories about vaccines, has already highlighted the news that several European countries are stopping using the vaccine.
Where the vaccine could make a huge difference is in the developing world, especially in Africa, where vaccine supply is far behind. The Biden administration is already under pressure to donate pre-made doses of the AstraZeneca vaccine to poorer nations, the New York Times reported on March 11. Meanwhile, COVAX – a partnership between the WHO, the Coalition for Epidemic Preparedness Innovations and Gavi, the Vaccine Alliance, to provide affordable vaccines to poorer countries – is based on the use of the AstraZeneca vaccine to provide hundreds of millions doses throughout the developing world.
“Security is our primary concern: We know that the national authorities and the WHO are closely monitoring the situation and the COVAX Facility will follow their guidance and recommendation,” a Gavi spokeswoman told BuzzFeed News. “At present, no causal link has been established between the vaccine and thromboembolic events in individuals, and the vaccine remains an important and effective public health tool in combating this pandemic.”