BERLIN — The European Union's regulator on Friday authorized the Oxford-AstraZeneca coronavirus vaccine for use in the 27-country bloc, expanding its tools to fight the pandemic even as it continued to feud with AstraZeneca over a supply shortage.
But inconsistent dosing in its clinical trials has muddied assessments of its effectiveness. And some governments have raised concern about a lack of data on the efficacy in people 65 and older, who represented only 6 percent of trial participants but account for a majority of coronavirus deaths and are high on most countries’ vaccination priority lists.
The United States is waiting for further trial data before authorization. Germany announced Thursday that it would recommend the vaccine only for adults younger than 65. And just hours before the European regulator gave its judgment, French President Emmanuel Macron told reporters in Paris that it seems “quasi-ineffective” among older people.
The European Medicines Agency, though, approved the vaccine for everyone 18 and older, saying that while it is not yet known how well the vaccine will work for older people, “protection is expected, given that an immune response is seen in this age group and based on experience with other vaccines.”
Britain and India have also authorized it for all adults.
“This has been a difficult year for many, and it’s caused a lot of hardship, not just in Europe but across the globe,” said Emer Cooke, executive director of the E.U. regulatory agency. “But let’s not forget that this year has seen progress at an unprecedented scale and speed in scientific terms.”
The regulatory decision came amid conflict between the E.U. and AstraZeneca, which has said its vaccine deliveries to the E.U. would fall short by as much as 60 percent this quarter after problems at a manufacturing site in Belgium. At the same time, the firm has been delivering large vaccine shipments to Britain.
The E.U. has threatened legal action, accusing AstraZeneca of using E.U. funds to make vaccine doses and then failing to live up to its contract.
The company, which has said it will provide its vaccine during the pandemic without turning a profit, maintains that it has met its contractual obligation of making a “reasonable best effort.”
Making vaccines is “extremely complicated,” AstraZeneca chief executive Pascal Soriot said at a Friday news conference. “It’s not like doing an orange juice.”
On Saturday, in a significant escalation, the E.U. will introduce a requirement that coronavirus vaccines manufactured in its territory will need approval before export. The measure will remain in place until the end of March. Vaccines being sent to lower- and middle-income countries will be exempt, top E.U. officials said. But doses being sent to Britain — the heart of the dispute with AstraZeneca — will be subject to the controls, which amount to an export ban if E.U. countries choose to decline permissions to send them out of the bloc.
“The challenges we now face left us with no other choice but to act,” said European Commission Vice President Valdis Dombrovskis. “We paid these companies to increase production, and now we expect them to deliver.”
European governments are under pressure as they face surging coronavirus cases, increasingly driven by the more transmissible variant of the virus first identified in Britain, while they also nervously eye a variant identified in South Africa that looks as though it could be less responsive to some vaccines.
The E.U. had sought to hedge its bets by preordering multiple vaccines — some say not enough. It has authorized two others at this point, the Pfizer-BioNTech and Moderna vaccines. But limited supply has meant that while strict lockdown orders remain in effect in many countries, inoculation campaigns have ground to a halt in certain regions. Less than 2 percent of the E.U.’s 450 million inhabitants have received a shot — and many in that group have gotten only the first of two doses.
European regulators said Friday that the AstraZeneca approval process had been challenging — they had to navigate around gaps in the data and mistakes in dosing — but that authorities would have come under fire if they had withheld a vaccine from the most vulnerable despite having no safety concerns and seeing indications that it gives at least some protection.
“We’d be criticized either way,” Bruno Sepodes, vice chair of the European Medicine Agency’s Committee for Medicinal Products for Human Use, said of the dilemma the regulator faced.
The regulator judged the vaccine to be 60 percent effective, ignoring trial participants who were given the wrong dosing during trials and appeared to have been better protected — its approval was for the standard dose.
By contrast, Germany’s vaccination committee said AstraZeneca’s data was simply not extensive enough. According to its breakdown of the trial data, one person among the 341 people over 65 who received the AstraZeneca vaccination was infected, compared with one infection in the control group.
“No statement can be made about the efficacy and safety for older people,” it said.
AstraZeneca has said the immune response observed among that age group has still been equal to that of younger trial participants, indicating strong protection. While there is more-limited data on the elderly, it “doesn’t mean that translates into a lack of protection,” said Oxford Vaccines Group director Andrew Pollard, who has been leading clinical trials. “It’s perhaps a misunderstanding,” he said of Macron’s assessment. “Having less evidence doesn’t mean that there’s a negative there.”
The E.U.’s contract with AstraZeneca is for 300 million doses, with the option for 100 million more. The vaccine was expected to make up the bulk of E.U. supplies in the first quarter for the year.
The bloc has purchased 160 million doses of the Moderna vaccine, enough to vaccinate 80 million people. Brussels has also recently boosted its initial order with Pfizer and BioNTech to allow it to buy up to 600 million doses.
In a news conference Friday, German Health Minister Jens Spahn said Germany is facing “a few hard weeks” of vaccine shortages. Given the restrictions on use of the AstraZeneca vaccine in Germany, Berlin has said that it will use the 3 million doses it expects to get next month to inoculate younger people within high-
priority groups, such as medical workers.
“We are living in and with the biggest crisis since World War II,” Spahn said, but adding a note of optimism. “What I think is important to see,” he said, is “the way out of the pandemic of the century has begun.”
Birnbaum reported from Riga, Latvia. Quentin Ariès in Brussels and Luisa Beck in Berlin contributed to this report.