Healthcare experts predict that a new surge of COVID-19 cases will hit the U.S. around Thanksgiving as the holiday season begins. Thanks to vaccines, the damage won’t be as devastating as last year — but it will be bad.

According to NBC News, there’s a basic level of protection that will make the virus less likely to linger but unless more people get vaccinated and follow common sense precautions, we will see spikes in many communities.

“I don’t think this spike will be as bad as last winter because we have vaccines available and the approval for younger age groups is a big game changer, especially in hospitalizations and death,” said Monica Wang, an associate professor at the Boston University School of Public Health.

But the threat of another COVID-19 surge is real, and California Gov. Gavin Newsom warned “COVID is not taking the winter off.” In fact, the Institute for Health Metrics and Evaluation (IHME) at the University of Washington projects the winter surge is already underway.

“We see increasing evidence in the Northern Hemisphere that the expected winter surge has started to unfold,” said Dr. Christopher Murray, the director of IHME. Murray says that three factors are fueling the current surge. Colder weather is driving people indoors, vaccine immunity is waning, and fewer people are wearing masks this year.

But more than two-thirds of Americans have now been vaccinated and that means the number of new cases should be less severe than last year and result in fewer hospitalizations and deaths, says NBC News.

Wang predicts that some states such as Wyoming, Alaska, Montana, North Dakota, and Utah may be hit harder than others because of their low vaccination rates. Epidemiologists overall do not see a good COVID-19 future this winter.

“I don’t know what’s going to happen over the next few weeks. But I have a feeling it isn’t going to be pretty,” said Michael Osterholm, an infectious disease expert at the University of Minnesota, according to CNN.  Diagnoses and hospitalizations are already increasing in Michigan, with hospitalizations up 20% in the past week. Dr. Nick Gilpin, the director of infection prevention at Beaumont Health, a healthcare system in Michigan, told CNN that Metro Detroit is once again becoming a trouble spot for COVID-19 infections.

“I have a feeling we’ll be in this world for the next couple of months because I don’t see that much can change this unless people radically change their behavior. This could be a four- or five-month affair.” Gilpin blames the unvaccinated and a refusal to wear masks for the current COVID-19 surge.

Colorado has seen a 30% increase in cases in the past week and Gov. Jared Polis signed an executive order saying everyone over the age of 18 is eligible for the booster shot. California and New Mexico have also expanded virus booster access, according to U.S. News & World Report. West Virginia and New York City are also allowing all adults access to boosters. Epidemiologists praise the states’ decisions since science is proving that three shots are needed to be protected, says CNN. The Food and Drug Administration is considering extending authorization for booster doses of Pfizer’s vaccine to all adults.

Osterholm agrees with the booster shot for all but says that the first dose is critical so that more people get vaccinated in the first place. An estimated 60 million Americans remain unvaccinated — and that’s plenty to power a surge of new cases.

“Overall, there’s still a lot of human wood left for this coronavirus to burn,” he said. Osterholm admitted he is pessimistic about the weeks and months ahead if people don’t pay attention to the warnings: get vaccinated and mask up.

“People are moving out and about like there is no COVID-19,” he told CNN. “We are going to see Americans traveling — Thanksgiving and all the way to the New Year. We are going to see a surge, and that surge is going to be very bad.”