BRUSSELS -- Vaccinations against the coronavirus could start in the 27 European Union nations by Christmas and member countries must urgently prepare their logistical chains to cope with the rollout of hundreds of millions of doses of the vaccines, according to a top EU official.

Hailing the likelihood that “there's finally light at the end of the tunnel,” European Commission President Ursula von der Leyen told EU lawmakers Wednesday that “the first European citizens might already be vaccinated before the end of December.”

The commission, the EU's executive arm, has agreements with six potential vaccine suppliers and is working on a seventh contract. The deals allow it to purchase over 1.2 billion doses, more than double the population of the bloc, which stands at around 460 million people. Some vaccines would require two doses to be effective.

On Tuesday, Brussels said it would sign a contract for up to 160 million doses of the experimental coronavirus vaccine developed by Moderna, which the company says appears to be 94.5% effective, according to its preliminary data.

But von der Leyen said that while vaccines are important, “what counts are vaccinations. ”

“Member states must get ready now. We're talking about millions of syringes, we're talking about cold chains, we're talking about organizing vaccination centres, we're talking about trained personnel that is there. You name it. All this has to be prepared,” she warned.

At Brussels Airport, Koen Gouweloose, the CEO of Swissport Cargo Services, told The Associated Press during a tour of his company's facilities that “what we expect is that there will be a huge volume coming through.”

Vaccine doses, from companies within Europe and from outside, will be temporarily stored in a refrigerated warehouse, and if necessary packed in dry ice, before they're shipped out by road, rail or air.

“We are in the middle of Europe and we have connections to many parts of the world,” said Gouweloose, whose facility routinely handles vaccines and was set up three years ago to help manage an Ebola virus outbreak. “We are prepared, everything is done, tested.”

Brussels Airport is also a major transport hub for Africa, and while von der Leyen has said the commission's aim is to secure vaccines for European citizens, she said it has helped to raise almost 16 billion euros ($19 billion) for tests, treatment and vaccines worldwide.

Despite the cautious optimism as outbreaks in a number of European countries start to plateau, Von der Leyen urged citizens to continue respecting restrictions, even as the measures harm businesses, further damage coronavirus-ravaged economies and put people through social and mental hardship.

“With nearly 3,000 deaths a day, COVID-19 was the number one cause of death in the EU last week. Hospitals remain under stress, and in some regions some intensive care units are overwhelmed,” she said.

“We must learn from the summer and not repeat the same mistakes. Relaxing too much is a risk for a third wave after Christmas,” von der Leyen said, adding that “this Christmas will be different, and yes, it will be quieter.”

Given its location in western Europe, bordering four EU countries, and that it's host to a number of big pharmaceutical companies, Belgium is set to become a hub for distributing the vaccines across the continent, but also into Africa.

Mark Carlson in Brussels contributed to this report.