70% of EU adults now fully-vaccinated against Covid

It means some 256 million adults in the EU have now received the full vaccine course against the virus, after a slow start earlier this year.

However, the most recent, late August, figures from the European Centre for Disease Prevention and Control show that uptake also varies significantly across the 27 EU states.

At the bottom is Bulgaria with only 19.3 percent of its adult population fully-vaccinated, followed by Romania (31.9 percent) and Latvia (45.5 percent). Malta is at the top with 90.3 percent, followed by Ireland (85.5 percent) and Denmark (83.5 percent).

The number of Bulgarian adults with a single dose of the vaccine at 21.1 percent is also the lowest in the EU, followed by Romania (32.8 percent).

A Bulgarian government spokesperson was not immediately able to respond to questions on why its uptake is so low.

Like across all EU states, the vaccine roll out is run by national authorities. Bulgaria received over five million doses and Romania almost 16 million.

Possible reasons behind Bulgaria's low figure may be linked to vaccine hesitancy, mismanagement and political upheavals. Bulgaria had also relied on AstraZeneca, a company which had failed to deliver the requested doses.

When those doses finally became available, public demand for the vaccine further dropped amid reports of rare blood clots.

The low demand led to national authorities trying to sell or donate soon-to-expire doses. Sofia gave 150,000 doses to western Balkan states.

Romania did the same, even as the more-contagious Delta variant is sending people to hospitals. Bucharest had sold Ireland 700,000 additional doses and over a million to Denmark.

"We need many more Europeans to vaccinate rapidly to avoid a new wave of infections," said von der Leyen, on Tuesday. She said the vaccinations could stop the emergence of new variants.

The commission in May signed a new contract with BioNTech-Pfizer to deliver 1.8 billion doses up until 2023.

It has also exercised an option for 150 million doses of the second Moderna contract. Other contracts may follow, if necessary, it said.