The World Health Organization is urging the public to practice Covid mitigation tactics – including masking and distancing – regardless of vaccination status as cases surge across Europe heading into the holiday season.

Some countries and communities have been lured into a “false sense of security” that the pandemic’s over and the vaccinated are fully protected against Covid, WHO Director-General Dr. Tedros Adhanom Ghebreyesus told reporters during an update Wednesday in Geneva.

He noted that Covid vaccines “save lives” and lower the risk of severe disease and death, but the vaccinated can still contract and spread the virus as social mixing returns to pre-pandemic levels.

“Even if you’re vaccinated, continue to take precautions to prevent becoming infected yourself, and to infecting someone else who could die,” Tedros said. “That means wearing a mask, maintaining distance, avoiding crowds and meeting others outside if you can, or in a well-ventilated space inside.”

Tedros called Europe “the epicenter of the pandemic,” with “unsustainable pressure” facing both health-care systems and personnel. Europe represented 67% of the world’s total new Covid cases during the week ended Nov. 21 with more than 2.4 million infections, an 11% increase from the previous seven days, according to the WHO’s most recent weekly epidemiological update.

The WHO’s office covering Europe and Central Asia said Tuesday that those regions have surpassed a combined 1.5 million Covid deaths and could suffer 700,000 more fatalities by March 2022. The organization expects that intensive care units in 49 of the region’s 53 countries could experience high or extreme stress over the next four months.

Governments rolling back public health measures are fueling Europe’s current outbreak, said Dr. Mike Ryan, executive director of the WHO’s Health Emergencies Program.

“In Europe, even in the midst of a very, very strong resurgence in cases, and even in the midst of some of those countries under huge pressure in their health systems, we’re seeing pre-pandemic levels of social mixing, gathering and many other things,” Ryan said. “And the reality is the virus will continue to transmit intensely in that environment.”

Though the majority of reported Covid cases worldwide are in Europe, Tedros added that “no country or region is out of the woods” just yet. But expanding vaccination coverage, wearing masks, using distancing, and improving ventilation indoors can help drive down Covid transmission without resorting to lockdowns heading into the holiday season, said Maria Van Kerkhove, the WHO’s technical lead on Covid.

Covid infections are also rising in the U.S., with more than 95,000 new cases reported daily on average, according to data from Johns Hopkins University. More than 1,100 people are dying a day in the U.S. from the virus on average, according to Hopkins.

More than 51,000 Americans are currently hospitalized with Covid-19, according to a seven-day average of Health and Human Services data as of Wednesday, up 7% over the past week.

The U.S. Centers for Disease Control and Prevention says unvaccinated individuals ages 2 and older should wear a mask in indoor public settings. The fully vaccinated should wear facial coverings indoors or in crowded outdoor areas in places with elevated Covid transmission, according to the agency. The CDC also requires masks onboard planes, trains and buses, as well as within all transportation centers.

CDC guidance also advises six feet of distance between people who don’t live in the same household, particularly for those at high risk for severe Covid symptoms.

Dr. Scott Gottlieb, former head of the U.S. Food and Drug Administration and a Pfizer board member, told CNBC that more vaccinated people are contracting the virus than people realize due to weak monitoring of breakthrough infections in the U.S.

“At this point I think we need to accept that there’s a lot of breakthrough infections happening, particularly people who are out a significant portion of time from their original vaccination,” Gottlieb said. “There’s going to be retrospective studies that identify this, but we’re not doing a good job of tracking this in real time. And this is the argument for people to go out and get boosters,” he said.

The U.S. cleared Pfizer and Moderna boosters for all adults on Friday. Johnson & Johnson boosters were cleared by the CDC in October. The WHO has criticized the broad distribution of boosters in wealthy nations because people in poorer countries have very limited access to vaccines.

The Netherlands entered a partial lockdown on Saturday, while Austria’s fourth full Covid lockdown began on Monday, with a nationwide vaccine mandate taking effect Feb. 1. Germany is also weighing whether to introduce a lockdown as the country’s seven-day new case average reached a record-high of more than 53,100 per day on Tuesday, up 29% from the week before, according to a CNBC analysis of data from Johns Hopkins University.

The White House on Monday said the Biden administration has no plans for a lockdown, pointing to rising vaccination rates and new therapeutic treatments that are coming online. The U.S. government has purchased 10 million courses of Pfizer’s Covid treatment pill, Paxlovid, which demonstrated high efficacy in preventing hospitalizations during a clinical trial.

“We can curb the spread of the virus without having to in any way shut down our economy,” White House coronavirus response coordinator Jeff Zients told reporters during a briefing. “We have 82% of people now with one shot and more and more people getting vaccinated each week.”