Questions about a link between the AstraZeneca COVID-19 vaccine and blood clotting is leading a number of European countries to halt its usage, even as doctors, health officials, and the vaccine’s manufacturers continue to encourage its deployment in fighting the pandemic.
Germany, France, and Spain are among what the Associated Press calls “a cascading number of European countries” stopping use of the vaccine after “AstraZeneca said there have been 37 reports of blood clots out of more than 17 million people vaccinated in the 27-country EU and Britain. The drugmaker said there is no evidence the vaccine carries an increased risk of clots.”
The report goes on to say that “the incidence of clots is much lower than would be expected to occur naturally in a general population of this size and is similar to that of other licensed COVID-19 vaccines.” The World Health Organization noted that the blood clotting incidence isn’t greater than would emerge in the general population, and has not yet established that the vaccine is behind the clots.
That is leading some health experts to wonder why such drastic measures are being taken.
“The decisions by France, Germany, and other countries look baffling,” Dr. Michael Head, senior research fellow in Global Health at the University of Southampton, told CNBC.
“The data we have,” he said, “suggests that numbers of adverse events related to blood clots are the same, and possibly, in fact, lower in vaccinated groups compared to unvaccinated populations.”
He also warned that “halting a vaccine roll out during a pandemic has consequences. This results in delays in protecting people, and the potential for increased vaccine hesitancy, as a result of people who have seen the headlines and understandably become concerned. There are no signs yet of any data that really justify these decisions.”
The New York Times added that “blood clots are common in the general population, and health authorities suspect that the cases reported in vaccine recipients are most likely coincidental and not related to the vaccination.”
“There are a lot of causes of blood clotting, a lot of predisposing factors, and a lot of people who are at increased risk—and these are often also the people who are being vaccinated right now,” Mark Slifka, a vaccine researcher at Oregon Health and Science University, told the New York Times.
The United Kingdom, Canada, and Australia are all still utilizing the AstraZeneca vaccine, and are looking to reassure citizens about its use. As noted by CNBC, the WHO, in tandem with Europe’s drug regulator and the International Society on Thrombosis and Hemostasis, have all recommended that countries continue to use the vaccine.
A March 15 Reuters report noted that Mexico is also still using the vaccine, and has in fact requested to tap into the U.S.’s stockpile via loan.
The U.S. has not yet approved the AstraZeneca vaccine for use, though the company is expected to apply for approval in the coming weeks.
In the U.K., nearly 10 million doses of the AstraZeneca vaccine have been administered. The New York Times reported “data found that at least some clotting conditions, while extremely rare, were equally prevalent for people vaccinated with AstraZeneca’s vaccine compared to those who got Pfizer’s product.” The article went on to note, however, that “abnormally low platelet levels were more common among people who got AstraZeneca’s vaccine.”
“We don’t want to ignore a signal that could indicate a larger problem,” Dr. David Wohl, director of the vaccine clinic at the University of North Carolina, said. “But at this point it’s premature to think AstraZeneca causes thrombosis.”