More than a dozen countries have suspended deployment of the AstraZeneca-Oxford University vaccine after cases of blood clots were reported.
Chaiwat Subprasom/SOPA Images/LightRocket via Getty Images
More than a dozen countries have suspended deployment of the AstraZeneca-Oxford University vaccine after cases of blood clots were reported. Per data received as of March 8, 17 million people in the European Union and United Kingdom have received the vaccine and there have been 15 cases of deep vein thrombosis and 22 cases of pulmonary embolism.
Incidences were first reported in Denmark and Norway, who halted distribution, followed by Germany, France and other countries. Germany’s Health Minister Jens Spahn admitted it was a “very low risk” but would be above average if it was actually linked to the vaccine.
Medical professionals in the U.S. are pushing back, working to minimize the public’s fears that vaccines may be unsafe. The European Medicines Agency (EMA), the European equivalent of the U.S. Food and Drug Administration (FDA), has argued that the benefits of the vaccine “outweigh the risks of side effects.” It is holding a meeting today to review the findings. The World Health Organization (WHO) has also urged countries to continue using the AstraZeneca vaccines.
On March 14, AstraZeneca issued a statement, noting “A careful review of all available safety data of more than 17 million people vaccinated in the European Union (EU) and U.K. with COVID-19 Vaccine AstraZeneca has shown no evidence of an increased risk of pulmonary embolism, deep vein thrombosis (DVT) or thrombocytopenia, in any defined age group, gender, batch or in any particular country.” In fact, the company pointed out, “This is much lower than would be expected to occur naturally in a general population of this size and is similar across other licensed COVID-19 vaccines.”
Even if the vaccine is linked to the blood-clotting, the incidence of it is extremely rare, far rarer than hospitalization and death from COVID-19.
William Schaffner, an epidemiologist and professor of preventive medicine at Vanderbilt University, told CNBC, “There’s now been a pall over this vaccine. I think if the vaccine is cleared—not guilty—there will have to be a substantial public relations effort made in Europe and around the world in order to restore confidence in this vaccine.”
The AstraZeneca-Oxford vaccine has not yet been authorized by the FDA, although Anthony Fauci, White House Chief Medical Officer and director of the U.S. National Institute of Allergy and Infectious Diseases (NIAID), told lawmakers yesterday that there will probably be sufficient safety and efficacy data in April for an Emergency Use Authorization (EUA).
“The entire process is both transparent and independent, and we explain that to people and take the time to address their hesitancy without being confrontative,” Fauci told the House Committee on Energy and Commerce.
Francis Collins, director of the U.S. National Institutes of Health (NIH), told Reuters Monday that he was “pretty reassured” by what European regulators have been saying, primarily that the blood-clotting issues are by chance.
“I was a bit surprised that so many countries decided to put pause on the administration of the vaccine, especially at a time where the disease itself is so incredibly threatening in most of those countries,” Collins later told CNN on Wednesday. But he also added that he doesn’t have access to the “primary data that might have caused them to be alarmed.”
Schaffner emphasized that when you begin mass vaccinations, particularly ones that target older adults, “medical events occur in that population just every day, even without vaccines. It’s possible that if you get vaccinated on Monday, certain medical events will occur on Tuesday, Wednesday, Thursday and Friday. The question is: Did the vaccine accelerate, precipitate or causes these events?”
Although it seems likely that AstraZeneca-Oxford will submit the vaccine for an EUA in the U.S. soon, possibly in April, the European situation does complicate matters. At this time, the vaccine group hasn’t submitted to the FDA. The U.S. Phase III trial is expecting a readout soon.
William Moss, a vaccines expert from Johns Hopkins University, said, “The FDA requires that at least half of the participants have two months of follow-up. That’s what they required for Johnson & Johnson, Pfizer, and Moderna. The company needs to kind of put all that together, all those data together and then present it to the FDA.”
Bruce Walker, an immunology expert from the Harvard Medical School, noted, “AstraZeneca vaccine right now is on hold in many countries in Europe because of concerns about whether it may be associated with blood clotting disorders. I think the FDA would be remiss if they didn’t, you know, look at what’s coming out of Europe.”
AstraZeneca apparently has initiated an independent review of its data from its Phase III trial in the U.S., that involved more than 32,000 volunteers.
“The main thing that’s going to be looked at is the efficacy and safety demonstrated in the U.S. clinical trials of the medication and among the safety features that they’ll look at will include any episodes of clotting and bleeding,” said David Hirschwerk, an infectious disease expert at Hofstra University’s Zucker School of Medicine. “It is almost certain that they’ll take into consideration the concerns that were raised in Europe.”
He added, “If it is found that there is a significant risk of clotting or bleeding then I think it stands to reason that there’s going to be a lot of hesitancy to approve it and, naturally, there’s going to be a lot of hesitancy from our communities to accept this vaccine.”
At this time, however, there’s no apparent link between the blood clotting and the vaccine, and the incidence itself is very low.
