Topline
Countries around the world have moved to restrict the use of the Oxford-AstraZeneca Covid-19 vaccine after British and European regulators found a possible link between the shot and very rare blood clotting, shaking public trust and complicating immunization programs despite expert consensus that the vaccine is safe, effective and has benefits that far outweigh any possible risks.
Some countries are restricting use of AstraZeneca’s Covid-19 vaccine after reports of a possible … [+]
Key Facts
The U.K.’s medicines regulator (MHRA) said people under the age of 30 should be offered an alternative to the AstraZeneca shot Wednesday, an abrupt course correction after ministers spent weeks defending the vaccine.
MHRA head Dr. June Raine emphasized that while the benefits of vaccination continue to outweigh any possible risks, this trade-off is more “finely balanced” in young people, who are believed to be more vulnerable to the clotting and are at less at risk from Covid-19, particularly in countries with high levels of vaccination like the U.K..
Europe’s medicines regulator (EMA), which also acknowledged a possible risk of blood clotting Wednesday, did not restrict its use—it recommended it be noted as a very rare side effect—but its report prompted Spain, Italy and Belgium to join a number of other European countries, including France and Germany, in limiting the shot to those aged around 60 and up (there is no unified policy).
Australian Prime Minister Scott Morrison said the nation’s health advisers recommended people under 50 receive an alternative vaccine Thursday “out of an abundance of caution” and in recognition of the country’s low incidence of Covid-19, adding that the country’s vaccination program, which uses AstraZeneca and Pfizer vaccines, will need a major “recalibration” to accommodate the change.
The Philippines and South Korea suspended the shot for use in people under 60, citing the European investigation, though South Korean officials rapidly reversed course amid the highest levels of cases since early January.
Canada restricted the vaccine for use in those under 55 in late March, a precautionary measure in response to reports of blood clots that was taken a week after regulators gave the shot the green light.
Surprising Fact
In a press briefing announcing the agency’s findings, the EMA’s head of data analytics, Peter Arlett, compared the vaccine with the contraceptive pill millions take every day. Arlett said you might expect to see about four cases of excess blood clots for every 10,000 people treated for a year. This figure is substantially higher than those being discussed with this vaccine.
Key Background
Regulators, even those suspending or restricting the shots use, uniformly stress the benefits and overall safety of the vaccine. This has been determined by rigorous medical testing and the risks from Covid-19 are considerably greater than those possibly presented by the vaccine. Even if there is a rare side effect of blood clotting—as the EMA has labeled it—it would still be considered to be a very safe product and the incidence of .
What We Don’t Know
Experts are still unsure what causes the blood clotting or if there is a definitive link, experts at the EMA and MHRA said Wednesday. It is also possible other vaccines on the market are also associated with blood clots, Professor Ian Douglas, professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine, said. “We need to remember this doesn’t mean other vaccines are not also associated with rare clots, just that we have less evidence and experience with them at the moment.”
Big Number
20 million. As of March 31, the MHRA says this is how many doses of the AstraZeneca vaccine have been administered in the U.K.. By this point, 79 cases of rare blood clotting had been recorded, 19 of whom died, working out at an overall risk of 4 people in one million being vaccinated.
What To Watch For
Whether the drug is approved by the U.S. Food and Drug Administration, which could prove influential globally. The company has said it intends to apply for emergency approval off the back of an ongoing clinical trial that suggests it is 76% effective against symptomatic Covid-19.
Further Reading
European Scientists Say They Know Why AstraZeneca’s Vaccine Is Causing Rare Blood Clots (Forbes)
AstraZeneca Vaccine 100% Effective In Preventing Severe Disease And Hospitalizations, U.S. Trials Show (Forbes)
Europe’s Mixed Messages On AstraZeneca Vaccine Jeopardize Global Covid Response (Forbes)
EU Agency OKs AstraZeneca Vaccine Ruling Out Broad Link To Blood Clotting (Forbes)
Experts Defend Safety Of AstraZeneca Covid-19 Vaccine After Several Countries Suspend The Shot (Forbes)
Politics, Not Science, May Be Behind Suspensions Of AstraZeneca’s Covid Vaccine (Forbes)
Asia’s rising coronavirus cases a worry as vaccine doubts cloud campaigns (Reuters)
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