The world’s two leading medicines regulators have reached different decisions on a third dose of the BioNTech/Pfizer COVID-19 vaccine — and it’s partly because of the complexity of the EU, according to the European Medicines Agency.
On September 22, the U.S. Food and Drug Administration authorized the use of the vaccine as a third, or booster, dose for all over 65s, and only those over 18 who are at greater risk from infection, such as those with underlying illnesses or frequently exposed to the virus, like health workers.
By contrast, the European Medicines Agency said on Monday that the third dose can be given to all healthy people over 18 at least six months after their second dose.
Both agencies were tasked with reviewing whether the benefits of having the third shot are outweighed by the risks of any side effects. And both agencies assessed the same supporting data, the EMA confirmed to journalists Tuesday.
However, Europe’s vaccine rollout is slightly different from the U.S. program, and this played into the broader opinion by the EMA, said Marco Cavaleri, head of vaccines at the EU agency.
“The conclusions on the data are pretty similar,” he said, “but the implementation in terms of regulatory decision are slightly different because we are working in a much more complex environment in Europe.”
Cavaleri said epidemiological data might be different across different countries and there is different use of vaccines across the EU.
The U.S. has relied heavily on the use of the mRNA vaccines from BioNTech/Pfizer and Moderna, and later the Johnson & Johnson vaccine. Europe has also authorized the Oxford/AstraZeneca vaccine, while a handful have also administered vaccines from Russia and China, which are not centrally authorized in the EU.
Meanwhile, data on the epidemiology in Europe and vaccines efficacy are “evolving very rapidly,” Cavaleri said.
“Therefore we prefer to keep a bit of a broader approach … looking at what is the effect of the booster overall more than entering into what kind of population will be more in need, at this point in time,” he said.
The data showed that antibody levels against the virus increased threefold after the booster, and it was “overall safe… clearly showing that the benefit risk of the booster dose is positive.”
He noted, however, that the EMA is awaiting further efficacy studies on booster doses. In its decision on Monday, the EMA pointed out that there is no direct correlation between antibody levels and efficacy.
Cavaleri underlined that the EMA’s decision was preliminary and allowed EU countries to administer boosters if this was their national decision. At least 10 EU countries have started to give booster doses, he noted, adding the agency tries “to align as much as possible with the member states on the use of the booster.”
The vaccine information will also specify that this is a “prudent recommendation,” he said.
The European Commission has yet to sign off on the EMA’s opinion, but this is expected within days.