BRUSSELS - European Union countries will receive 50 million more coronavirus vaccines produced by Pfizer and BioNTech in the second quarter, the head of the EU Commission said on Wednesday, as deliveries expected at the end of the year will be brought forward.

European Commission President Ursula von der Leyen said the earlier deliveries, which will start this month instead of in October, will take total supplies to the EU from Pfizer to 250 million doses in the second quarter in a move meant to compensate for lower supplies from AstraZeneca and possible problems with Johnson & Johnson.

"I am pleased to announce that we have reached an agreement with BioNTech-Pfizer to once again speed up the delivery of vaccines," she said.

"This will substantially help consolidate the roll-out of our vaccination campaigns."

Von der Leyen confirmed the Commission was in talks with Pfizer and BioNTech for a new contract for 1.8 billion doses to be delivered in 2022 and 2023, confirming a Reuters report last week.

The EU has already signed two contracts with the two companies for 600 million doses to be delivered this year. About 70 million shots were shipped in the first quarter.

Under the new contract "delivery schedules will be laid out on a monthly instead of quarterly basis," von der Leyen said, adding that production of the vaccines and their essential components will take place in the EU.

She also said on Wednesday that 100 million doses of vaccine had been so far administered in the 27-nation bloc, which has a population of nearly 450 million, since the beginning of the rollout in late December.

(Reporting by Francesco Guarascio @fraguarascio, Sabine Siebold and Jan Strupczewski; Editing by Mike Harrison) ((Francesco.Guarascio@thomsonreuters.com; +32 2 287 68 17;))