ROME >> European Union nations kicked off a coordinated effort today to give COVID-19 vaccinations to the most vulnerable among the bloc’s nearly 450 million people, marking a moment of hope in the continent’s battle against the worst public health crisis in a century.

Health care workers, the elderly and leading politicians got some of the first shots across the 27-nation bloc to reassure the public that the vaccinations are safe and represent the best chance to emerge from the pandemic.

“It didn’t hurt at all,” said Mihaela Anghel, a nurse at the Matei Bals Institute in Bucharest who was the first person to get the vaccine in Romania. “Open your eyes and take the vaccine.”

In Rome, five doctors and nurses wearing white scrubs sat in a semi-circle at the Spallanzani infectious diseases hospital to receive their doses.

“The message is one of hope, trust and an invitation to share this choice,” said one of the recipients, Dr. Maria Rosaria Capobianchi, who heads the virology laboratory at Spallanzani and was part of the team that isolated the virus in early February. “There is no reason to be concerned.”

Italian virus czar Domenico Arcuri said it was significant that Italy’s first vaccine doses were administered at Spallanzani, where a Chinese couple visiting from Wuhan tested positive in January and became Italy’s first confirmed cases. Only later would northern Lombardy become the epicenter of the outbreak in Europe. Italy now has the continent’s worst confirmed virus death toll at nearly 72,000.

“Today is a beautiful, symbolic day: All the citizens of Europe together are starting to get their vaccinations, the first ray of light after a long night,” Arcuri told reporters outside the hospital.

But he cautioned: “We all have to continue to be prudent, cautious and responsible. We still have a long road ahead, but finally we see a bit of light.”

The vaccines, developed by Germany’s BioNTech and American drugmaker Pfizer, started arriving in super-cold containers at EU hospitals on Friday from a factory in Belgium.

In the Los Olmos nursing home in the Spanish city of Guadalajara, northeast of Madrid, a 96-year-old resident and a caregiver were the first Spaniards to receive the vaccine.

“Let’s see if we can all behave and make this virus go away,” said Araceli Hidalgo, the elderly resident, after receiving her injection.

The Czech Republic was spared the worst of the pandemic in the spring only to see its health care system near collapse in the fall. In Prague, Czech Prime Minister Andrej Babis received his shot at dawn today and asserted: “There’s nothing to worry about.” Sitting next to him in a wheelchair was World War II veteran Emilie Repikova, who also received the shot.

Altogether, the EU’s 27 nations have recorded at least 16 million coronavirus infections and more than 336,000 deaths — huge numbers that experts still agree understate the true toll of the pandemic due to missed cases and limited testing.

All those getting shots will have to come back in three weeks for a second dose.

European Commission President Ursula von der Leyen released a video Saturday celebrating the vaccine rollout, calling it “a touching moment of unity.” The vaccination campaign should ease frustrations that were building up, especially in Germany, as Britain, Canada and the United States kicked off their inoculation programs with the same vaccine weeks earlier.

As it turned out, some EU immunizations began a day early in Germany, Hungary and Slovakia. The operator of a German nursing home where dozens of people were vaccinated Saturday, including a 101-year-old woman, said “every day that we wait is one day too many.”

Each EU country is deciding on its own who will get the first shots, with most vowing to put the elderly and residents in nursing homes first.

EU leaders are counting on the vaccine rollout to help the bloc project a sense of unity in a complex lifesaving mission after it faced a year of difficulties in negotiating a post-Brexit trade deal with Britain.

“It’s here — the good news at Christmas,” said German Health Minister Jens Spahn. “This vaccine is the decisive key to end this pandemic … it is the key to getting our lives back.”

Among the politicians who planned to get virus shots today to promote a wider acceptance of vaccinations were Slovakian President Zuzana Caputova and Bulgarian Health Minister Kostadin Angelov.

Meanwhile, the first cases of a new virus variant that has been spreading rapidly around London and southern England have now been detected in France and Spain. The new variant, which British authorities said is much more easily transmitted, has caused European countries, the United States and China to put new restrictions on travel for people from Britain.

Japan became the latest country to act, announcing it would temporarily ban all non-resident foreigners from entering through Jan. 31 as a precaution against the U.K.’s new variant.

Germany’s BioNTech has said it’s confident that its coronavirus vaccine works against the new U.K. variant, but added that further studies are needed to be completely certain.

The European Medicines Agency on Jan. 6 will consider approving a second coronavirus vaccine, this one by Moderna, which is already being used in the United States.