Monday’s move was a reaction to soaring COVID-19 infection levels in Europe, which have led many countries to reintroduce restrictions, in some cases specifically targeting the unvaccinated people who are driving the surge. Apart from the countries that Americans are being told to avoid, they are also being advised to steer clear of France and Italy unless they are vaccinated against the coronavirus.

Also on Monday, the European Union’s health commissioner told the European Parliament that the bloc’s travel rules will be amended this week, to stay ahead of countries going their own way as they scramble to respond to the situation. “We need to avoid fragmentation,” Stella Kyriakides said.

According to Bloomberg, the changes could include changes to the duration of validity for the COVID-19 vaccination certificates that people use to move between EU countries. Some countries, such as Greece, also want to see the digital certificates, which are used locally as well as for cross-border travel, start to include information on people’s booster status. France is already moving to block people from entry to restaurants and other facilities if they haven’t received a booster despite being eligible.

Germany only just introduced a new law last week that limits free movement for unvaccinated people, but its caretaker government—a new coalition is about to take power following elections in September—already wants more restrictions on entry to public spaces. “We are in a highly dramatic situation. What is in place now is not sufficient,” Chancellor Angela Merkel said Monday. (Merkel’s defeated CDU party was not behind the legislation passed last week.) Health Minister Jens Spahn said Tuesday that the situation in some regions of the country was “not only serious [but] now dramatic.”

Germany’s floating seven-day incidence rate, reflecting infections per 100,000 people, shot up from 386.5 to 399.8 over the last day. Saxony has the country’s highest rate at 969.9, which is perhaps no surprise as it borders Austria, where the rate is now slightly over 1,110. For context: When Germany adopted its now-expired Protection Against Infections Act back in April, the law included an “emergency brake” that would impose restrictions when a state cleared the threshold of 100 infections per 100,000 inhabitants over the preceding week.

Denmark, to Germany’s north, is also experiencing a new peak every day.

The Danish government had decided in September that it would be a good idea to remove the last of its coronavirus restrictions, because the epidemic was “under control.” At the time, the seven-day incidence rate was 113. Two months later, the administration performed a sudden u-turn, reacting to a rate of 253 by reintroducing restrictions. That was earlier this month. Now the rate is 466, which is even higher than the U.K. (422.7).

Denmark’s population is 76% fully vaccinated, which is more impressive than Germany’s 68%. However, hospitalization rates are increasing in both countries. “We therefore risk the health system soon being forced to prioritize in what they do. We’re not there yet, but things could go the wrong way,” University of Southern Denmark microbiology professor Hans Jørn Kolmos told The Local. In Germany, intensive-care units are filling up and running out of staff; a hospital in the state of Bavaria was forced to transfer patients to Italy last week.