Why Doesn’t the Vaccine Safety Debate Seem Settled?
In endorsing the AstraZeneca-Oxford shot, European regulators could have done more to answer lingering questions.
If European regulators cleared the Astra vaccine, why do questions remain about safety?
Photographer: Sai Aung Main/AFP via Getty Images
The European Union’s Covid-19 vaccination effort has been rocky, with inoculations lagging behind the U.S. and U.K. even as an increase in cases in the region has prompted fresh lockdowns. Most recently, concerns about blood-clot risks related to the AstraZeneca Plc-Oxford University vaccine — one of four given emergency use authority in the EU — led several countries to suspend the shot pending a fresh regulatory review from the European Medicines Agency. So it was good news, then, when officials from the EMA on Thursday backed the shot as safe and effective, saying the benefits of protecting against Covid-19 outweigh any risks.
The pronouncement wasn’t entirely clear cut, though. While officials said they did not think there was a link between the Astra vaccine and some rare blood-clotting events, they could not categorically rule out a connection. There were 18 cases of cerebral venous sinus thrombosis, or blood clotting that impacts the draining blood vessels of the brain, and seven cases of disseminated intravascular coagulation, a widespread clotting issue. This is out of 20 million doses of AstraZeneca’s vaccine, according to the EMA. It is technically difficult to prove a link in such rare instances and it will take more research and time. In the meantime, the EMA recommended a warning label be applied to the shot so people are aware of the potential risk. We asked Sam Fazeli, a Bloomberg Opinion contributor who covers the pharmaceutical industry for Bloomberg Intelligence, whether all doubts about the shot had been put to rest.