The EU is turning more heavily to BioNTech/Pfizer to make up for suspended Johnson & Johnson vaccine doses and for longer-term needs to fight the mutating coronavirus, its chief Ursula von der Leyen said Wednesday.

BioNTech/Pfizer is bringing forward delivery of 50 million doses to the second quarter, starting this month, to help make up for the shortfall of the J&J jabs that were meant to start rolling out, she said in a televised statement.

The European Union is also negotiating with BioNTech/Pfizer for 1.8 billion doses of a second-generation of its mRNA vaccine to combat variants, to be delivered in 2022 and 2023, she said.

"As we can see, with the announcement by Johnson & Johnson yesterday, there are still many factors that can disrupt the planned delivery schedules of vaccines," she said, referring to the company's decision to suspend European deliveries while rare blood clot cases possibly linked to its shot are investigated in the United States.

"It is therefore important to act swiftly, anticipate and adjust whenever it is possible," she said, announcing the second-quarter delivery of 50 million BioNTech/Pfizer doses originally scheduled for the fourth quarter of this year.

Von der Leyen said that would bring the total number of BioNTech/Pfizer doses for April, May and June to 250 million -- accounting for more than half of all jabs to be given in this quarter.

"I think this will substantially help consolidate the rollout of our vaccination campaigns," she said, noting that there have already been 100 million doses given in the bloc to date, with 27 million people fully vaccinated.

The European Union had a sluggish first-quarter rollout mainly because of vaccine supply constraints, especially by AstraZeneca which delivered less than a quarter of the 120 million doses it had promised.

Virus variants

Question marks are now above the adenovirus-type vaccines produced by AstraZeneca and Johnson & Johnson in the wake of suspected blood clots.

While the European Medicines Agency has authorised AstraZeneca for all adults, many EU countries have taken the precaution of limiting its use to only older segments of the population.

Von der Leyen made clear that BioNTech/Pfizer was increasingly the go-to supplier for the bloc, with no health problems so far associated with its mRNA vaccine which has proven to be highly effective against the main strains of the coronavirus present in the EU.

However there are concerns about emerging virus variants that could dampen the effect of current vaccines.

Von der Leyen said to address that, "at a certain point in time, we might need booster jabs to reinforce and prolong immunity" with vaccines that are effective against mutations.

"We need to focus now on technologies that have proven their worth: mRNA vaccines are a clear case in point. And based on all this, we are now entering into negotiations with BioNTech/Pfizer for a third contract," she said.

That would foresee the delivery of 1.8 billion second-generation BioNTech/Pfizer vaccine doses over next year and 2023.

"It will entail not only the production of vaccines, but also the essential components. All of that will be based in the European Union," von der Leyen said, indirectly referencing concerns that had arisen about supplies of AstraZeneca from Britain or Johnson & Johnson doses that were sent via the US for packaging.

The EU has made the production of vaccines on its territory -- already the main vaccine manufacturing powerhouse in the world alongside the US -- a condition of its forthcoming contracts.

"Other contracts with other companies may follow," von der Leyen said.