Nearly two years into the coronavirus era, much of Europe is once again facing a surge in cases and, in some countries, a return to lockdowns and restrictions that felt like a distant part of the pandemic.

This time around, unvaccinated residents are frequently the target of new measures. Overall, about 76 percent of adults in the European Union and 65 percent of the total population have been fully vaccinated, according to the European Center for Disease Prevention and Control.

In Austria, as of midnight Monday, about 2 million unvaccinated people will be subject to a lockdown lasting 10 days as cases rise.

In Germany, rattled by record-breaking levels of confirmed infections, the government has shied away from population-wide vaccine mandates, but officials have introduced mounting restrictions on those who haven’t had the jab. As of Monday in Berlin, only those residents who are vaccinated or who are recovered can eat out in restaurants or visit bars.

In the Netherlands, a three-week partial lockdown is underway, with restaurants and shops ordered to close early in an effort to get ahead of a spike in cases which could raise pressure on hospitals.

In Italy, a relatively early adopter of vaccine mandates after a devastating period, infection rates are among the lowest in Europe.

In Britain, which has continued to resist reimposing restrictions despite high case counts, Prime Minister Boris Johnson warned Monday that “storm clouds” were gathering over parts of the continent.

“We don’t yet know the extent to which this new wave will wash up on our shores but history shows we cannot afford to be complacent,” Johnson said. He urged those eligible in the United Kingdom to get booster shots and for those still waiting for initial doses to come forward.

Last week, Europe reported close to 2 million coronavirus cases, the “most in a single week in that region since the pandemic started,” World Health Organization Director General Tedros Adhanom Ghebreyesus said.

“Some European countries are now reintroducing restrictions to curb transmission and take the pressure off their health systems,” he said. “No country should be in this position almost two years in the pandemic.”

Fueled by vaccine hesitancy, slowing vaccination rates and the rollback of infection-control measures such as face mask mandates and travel bans, Europe is in many ways a test case for what life with both the virus and vaccines could come to look like after the pandemic itself is over.

Though vaccines against the coronavirus still remain limited for much of the world’s population, Europe was among the earliest regions to roll out immunization programs. In the year since, more contagious variants have fueled additional outbreaks as the virus has continued to spread among the unvaccinated and in breakthrough infections of the vaccinated.

No coronavirus vaccine can guarantee complete protection, but the shots significantly lessen the risk of catching the virus and of developing a severe case if a person does come down with a breakthrough infection.

Vaccination rates in Eastern Europe have remained lower overall than those in Western Europe. The recent surge in coronavirus cases began in the latter and is now hitting the former. Countries with vaccination rates in the upper 70 percent range have in turn fared better than their neighbors with vaccination rates hovering around 60 percent or below.

In Romania, where just 40 percent of the population is fully vaccinated, hospital wards have been stretched thin as hundreds of people have died a day from the virus in the last two months. The country reached a peak with over 590 confirmed dead on Nov. 2, with more than 90 percent of fatalities among the unvaccinated, according to the Associated Press.

Earlier this month, Latvia tightened its entry rules for almost all European countries. Latvia is facing one of the worst outbreaks in Europe along with having among the lowest vaccination rates.

The country’s new public health measures have targeted the unvaccinated. The Latvian parliament passed legislation which allows businesses to fire workers who refuse the shot or transfer to remote work. Lawmakers are not exempted as members of parliament who refuse to be vaccinated will lose pay and their right to vote on legislation.

European Commission spokesman Stefan De Keersmaecker said Monday that lockdowns in the 27-member bloc are a country-by-country decision. The European Center for Disease Prevention and Control concluded in a September study that countries with less than 55 percent to 65 percent of their total population vaccinated risk a significant case surge if they ease down pandemic restrictions right now.

“With case increases in almost all member states, the situation remains fragile and the vaccination coverage must continue,” he said.

Russia’s vaccination campaign has also lagged, a year into the availability of the country’s Sputnik V vaccine. A fourth wave has set records in daily cases and deaths, although the government proceeded with a scheduled rollback of a partial lockdown this week. But authorities have signaled that strict public mandates for the unvaccinated are on the horizon.

Only 40 percent of Russia’s population is fully vaccinated. One draft law would require people to have a QR code confirming vaccination, a medical certificate proving a previous infection or a medical exemption from the vaccine for anyone seeking to travel on intercity or international rail and air services. The code also would be needed to purchase tickets.

If the proposed legislation passes, it would come into force in February. QR codes might also be required for public places and restaurants, but those measures would depend on the region rather than nationwide.

William Booth in London, Isabelle Khurshudyan in Moscow, Loveday Morris in Berlin and Perry Stein in Brussels contributed to this report.