The European Union will buy an extra 100 million doses of Pfizer and BioNTech's Covid-19 vaccine, bringing the total from the two firms to 300 million doses, European Commission President Ursula von der Leyen said on Tuesday.
"We decided to take an additional 100 million doses of the BioNTech/Pfizer vaccine, which is already being used to vaccinate people across the EU," she said on Twitter.
"We will therefore have 300 million doses of this vaccine, which was assessed as safe and effective," von der Leyen added.
The plan comes after some of the vaccine candidates ordered by the EU faced unexpected delays in clinical trials, forcing the bloc and other wealthy nations to rely on shots from fewer manufacturers than initially planned.
The Pfizer/BioNTech shot, the first Covid-19 vaccine to be approved by Western drugs regulators, is being rolled out in countries including Britain and the United States.
Under the EU contract, the two firms have committed to rapidly deliver 200 million doses after regulatory approval for 15.5 euros ($18.8) apiece, EU officials told Reuters in November.
The extra 100 million doses would be supplied at the same price, but with the timetable to be negotiated, EU officials said.
With a population of 450 million, the bloc is now relying on the 200 million Pfizer shots it has already ordered for its first vaccinations.
In January, the EU is also expected to approve the shot developed by Moderna. It has an initial order of 80 million doses, with an option for 80 million more that will be exercised.
Both the Pfizer and Moderna vaccines require two doses per person. In total, the EU has booked nearly 1.3 billion vaccines in deals with Pfizer/BioNTech, Moderna, Johnson & Johnson, AstraZeneca/Oxford, Sanofi/GSK and CureVac, and has options to buy another 660 million.