In the COVID-19 vaccine game, there are two main kinds of players: those that use traditional vaccine technologies, such as AstraZeneca and Johnson & Johnson, and those that use newfangled “messenger RNA” technology, such as BioNTech/Pfizer and Moderna.

Now, with AstraZeneca’s and Johnson & Johnson’s offerings both having been inconclusively linked to rare, but dangerous blood clots, it is looking increasingly likely that Europe will go all-in on the latter kind from next year.

On Wednesday, La Stampa reported an unnamed source in the Italian health ministry as saying the European Commission would not renew its contracts with AstraZeneca and J&J after 2021, and would instead focus on mRNA technology.

The traditional approach to COVID-19 vaccine technology involves the use of a harmless, modified adenovirus—a chimpanzee virus in AstraZeneca’s case and a human virus in J&J’s—to provoke the immune response that results in inoculation. However, mRNA vaccines use lab-made genetic material to deliver instructions to the body that ultimately produce the same result.

The Commission itself wouldn’t confirm the report from La Stampa, saying only that it is keeping all its options open but would not “comment on contractual issues.”

However, at lunchtime Commission President Ursula von der Leyen dropped some heavy hints during a statement about the EU’s vaccine strategy.

“We need to focus now on technologies that have proven their worth,” she said. “mRNA vaccines are a clear case in point.”

‘A reliable partner’

Von der Leyen was effusive in her praise for BioNTech/Pfizer, which she said had just agreed to deliver an extra 50 million doses to the EU this quarter—vaccines that it was originally scheduled to deliver only in Q4.

Coincidentally, J&J was supposed to deliver 50 million doses of its vaccine to the EU in Q2, but on Tuesday it made the extraordinary decision to unilaterally suspend distribution.

This move is tied to U.S. uproar over the rare clotting issue—regulators on both sides of the Atlantic are scrambling to assess the actual risk—but, coming as it does after AstraZeneca’s repeated failure to make good on its EU delivery promises, it could serve as another strike against the adenovirus camp.

“I want to thank BioNTech/Pfizer,” von der Leyen said. “It has proven to be a reliable partner. It has delivered on its commitments and has been responsive to our needs.”

Now, she added, the Commission was entering into negotiations with BioNTech/Pfizer for a third contract that would see the delivery of 1.8 billion additional doses in 2022 and 2023—the EU only has 446 million inhabitants, but the Commission is thinking of the booster shots that may prove necessary, plus tweaked vaccines that could be needed to fend off newly mutated virus variants.

Von der Leyen added that the proposed deal would “entail not only the production of vaccines but also the essential components. All of that will be based in the European Union.“ That detail could prove crucial. Not only is there a global shortage of components, such as the bags in which vaccine cells are grown, but the U.S. has an export ban on components as well as vaccines.

So far, the Commission President said, 100 million vaccine doses have been administered in Europe, with 27 million Europeans having been fully vaccinated. With the exception of J&J, the vaccines all require two doses.

‘A few days’

It is certainly not clear that J&J’s vaccine will suffer the fate of AstraZeneca’s, which countries across Europe are now limiting to older patients, owing to those under 60 being statistically more likely to develop the rare clots.

No EU country has as yet placed any such limit on J&J’s vaccine—the first delivery arrived pretty much just as J&J’s self-imposed pause was announced, and the European Medicines Agency will only give a recommendation next week.

However, the decision by U.S. regulators to recommend a stateside suspension has echoed around the world.

Notably, the South African drug authority has recommended a pause there, too, while it examines data from both Johnson & Johnson and the U.S. Food and Drug Administration (FDA). J&J’s vaccine actually started rolling out in South Africa before any other country, including the U.S., but in the unusual context of an implementation study involving the nation’s health care workers.

The South African agency said its review process would probably take “a few days.” The FDA has also suggested that its pause will last only a few days.

However, the effect of the pause remains to be seen. While White House coronavirus coordinator Jeff Zients claimed the U.S. pause “should reassure the American public,” and South African Health Minister Zweli Mkhize said that country’s suspension “should provide comfort,” in Europe, the constant flip-flopping over AstraZeneca’s safety has seriously dented public confidence in the vaccine.

J&J had not responded to a request for comment at the time of publication.