ROME — It wasn't quite a mandate, but the announcement landed with nearly the same power.

After Italy said in late July that its coronavirus health passport would be required to go to the movies or dine indoors, daily bookings for inoculations soared. A new kind of patient started arriving at vaccination centers: people who had been wavering or reluctant. In one waiting room in Rome, Federica Puccetti, 19, said she still didn’t want the shot. But she had plans to go to the island of Sardinia. Inoculation had become the path to a normal vacation.

“Otherwise, you can’t do much of anything,” Puccetti said, and then a volunteer told her it was her turn.

In making its health pass a de facto ticket to daily social life, Italy has become representative of the new pressure tactics being deployed in several major European countries at a crucial stage of the pandemic.

Although the European Union vaccination campaign got off to an embarrassingly slow start, after seven months the bloc is in essentially the same position as the United States, with some 50 percent of the population fully vaccinated, and nearly 60 percent having received at least one dose.

That means hundreds of millions of people have significant protection against severe sickness and hospitalization. But countries also stand well shy of their goals, which include not just protecting people individually, but also vaccinating enough people that the virus cannot easily wreak havoc within communities. Success now hinges on convincing, or coercing, holdouts.

In country after country, some version of the same debate is unfolding about whether vaccination can and should be mandated for participation in workplaces, schools and social settings. Though only months ago the idea of such requirements seemed politically untenable, leaders have been rapidly reassessing, as the highly contagious delta variant spreads and some hospitals — in areas with low vaccination rates — are pushed back to the brink.

The Biden administration on Thursday announced mandate-like guidelines for the millions who work in the federal government, requiring them to be vaccinated or undergo repeated testing. Some U.S. states and major employers have passed rules for their workers.

“It’s still a question whether the federal government can mandate the whole country,” Biden said. “I don’t know that yet.”

In several major European countries, the answer to that question has been yes. France, Greece and Italy are requiring people to show their covid passports to go to restaurants, gyms, movie theaters and other places where people gather. And Britain said people will need to show documentation to enter nightclubs and other crowded venues starting in September. British officials suggested they were less concerned about enforcement than about motivating people to get vaccinated.

The rules stop short of being mandates, in that people can alternatively show proof of antibodies or a recent negative coronavirus test. The impracticalities, though, would mount: In Italy, an unvaccinated gymgoer, for instance, would need to get tested every two days to do regular workouts.

Italian Prime Minister Mario Draghi pitched the decision as a way to protect the country and reduce the chance of needing further restrictions. The policy also amounts to a test of how readily unvaccinated people might be persuaded when faced with the prospect of having second-tier privileges.

“Without a vaccine,” Puccetti said, “you’re marginalized.”

Western Europe, like the United States, has a strong strain of vaccine skepticism, but acceptance of coronavirus vaccines had already been rising faster among Europeans than Americans. In Italy, though there are blocks of coronavirus vaccine skepticism on both the left and far right, polls conducted before and after the new policy announcement suggest the group is small: Only 8 percent of the country is vehemently opposed, according to one recent survey. Another 7 percent describe themselves as undecided.

It is with that group — the undecideds — where inducements may hold the most sway.

At a vaccination center in Rome in late July, several people who had booked their first shots described themselves as having been on the fence, citing common reasons: Fear about potential long-term side effects that wouldn’t have been evident in vaccine trials. Uncertainty stemming from the speed at which vaccines were authorized. Confusion about the messaging from politicians, from news outlets and on social media. There were anecdotal stories about people who had been vaccinated and got sick anyway. Several mentioned seeing videos of people sticking magnets and coins to their shoulders after being inoculated, purported evidence that the vaccines contained traces of metal.

“They don’t want to be guinea pigs,” said Fabio Picchiarelli, a doctor at the vaccination center, summarizing the sentiments he had seen. He said he has on occasion tried to convince people, simply by showing them official information. Out of curiosity, he said, he had Googled the term “covid vax,” and was concerned about the amount of false information he saw.

“About 60 percent of what comes up is fake news,” Picchiarelli said.

In both France and Italy, the early indication is that near-mandates can drive a significant boost in sign-ups.

In the aftermath of French President Emmanuel Macron’s announcement, earlier in July, the country set new daily vaccination records for nearly a week.

Many of the people who booked appointments in the wake of the Italian announcement won’t receive vaccines until early August, but there are signals of a coming surge. Lazio, the region that includes Rome, had been receiving about 6,000 appointment requests per day before Draghi’s decision; it received 34,000 bookings on average in the days after.

The country is currently giving out shots at a pace four times that of the United States.

Earlier in the pandemic, many infectious-disease experts had suggested that vaccination rates of 70 or 75 percent might be enough to achieve herd immunity in the population. But the delta variant is so transmissible that some scientists say herd immunity might not be possible — especially given the existence of breakthrough infections. The goal, scientists now say, should be to vaccinate as many people as possible to cut down on the likelihood of easy community transmission and to protect by proxy children too young for the shots, as well as individuals with health conditions that make them ineligible.

“The rule is, you need to leave less wiggle room for the virus,” said Sergio Abrignani, an immunologist and a member of a scientific committee advising the Italian government. “The fewer unvaccinated individuals get together, the lower chances for it to circulate.”

Some three-quarters of Italians support the new requirements, according to polling — a level similar to France. But there has also been strident opposition, including some street protests, where leaders have called the move discriminatory and economically damaging.

Giorgia Meloni, the leader of a major Italian far-right party, bitingly referred to Italy’s green pass as a “government pass that authorizes social life.” Meanwhile, two eminent philosophers — among them, former left-wing Venice mayor Massimo Cacciari — released a statement warning that the idea was dangerous to democracy and would turn the unvaccinated into “second-class citizens.”

At the vaccination center in Rome, people getting their shots had more practical questions: about how the rules — which are set to take effect Aug. 6 — would possibly be enforced.

One restaurant manager, who had signed up for her shot hours after Draghi’s news conference, thinking it would be necessary to protect her job, said she worked at a bistro with 10 employees, and only two were vaccinated. Would they now be banned from working?

Others at the center said it was hard to imagine bars and restaurants, after suffering for more than a year, suddenly dedicating a doorman to weeding out customers without a valid health pass.

“I think many public places won’t care much,” said Marco Tinti, 19.

Pierpaolo Sileri, a deputy health minister, told The Washington Post that the rules would be enforced with fines.

“If everyone does their part,” Sileri said, “I don’t see any critical issues.”

After receiving her Moderna shot, Puccetti was directed to a waiting area and told to remain there for 15 minutes — a standard period of observation. She said she was a “little angry” that she had been coerced, but otherwise felt fine.

“No effect,” she said with a shrug. “This just means I can go to Sardinia.”

As she sat there, she said that she, too, had seen the videos about the metal content of the vaccines. She didn’t believe it, but she was tempted nonetheless to try the experiment for herself. So before she left the facility, she pressed a 20-cent euro coin to her left shoulder.

“This is ridiculous, I know,” she said, almost apologetically.

The coin fell to the floor.

Karla Adam in London and Loveday Morris in Berlin contributed to this report.