WASHINGTON • The contagious delta variant is driving up COVID-19 hospitalizations in the Mountain West and fueling disruptive outbreaks in the North, a worrisome sign of what could be ahead this winter in the U.S. While trends are improving in Florida, Texas and other Southern states that bore the worst of the summer surge, it’s clear that delta isn’t done with the United States. COVID-19 is moving north and west for the winter as people head indoors, close their windows and breathe stagnant air.

“We’re going to see a lot of outbreaks in unvaccinated people that will result in serious illness, and it will be tragic,” said Dr. Donald Milton of the University of Maryland School of Public Health.

In recent days, a Vermont college suspended social gatherings after a spike in cases tied to Halloween parties. Boston officials shut down an elementary school to control an outbreak. Hospitals in New Mexico and Colorado are overwhelmed.

In Michigan, the three-county metro Detroit area is again becoming a hot spot for transmissions, with one hospital system reporting nearly 400 COVID-19 patients. Mask-wearing in Michigan has declined to about 25% of people, according to a combination of surveys tracked by an influential modeling group at the University of Washington.

“Concern over COVID in general is pretty much gone, which is unfortunate,” said Dr. Jennifer Morse, medical director at health departments in 20 central and northern Michigan counties. “I feel strange going into a store masked. I’m a minority. It’s very different. It’s just a really unusual atmosphere right now.”

New Mexico is running out of intensive care beds despite the state’s above-average vaccination rate. Waning immunity may be playing a role.

FILE – Graham Roark, 8, receives the Pfizer COVID-19 vaccine for children 5 to 11 years from Lurie Children’s hospital registered nurse Virginia Scheffler at the hospital Nov. 5, 2021, in Chicago. First shots are averaging about 300,000 per day. (AP Photo/Nam Y. Huh, File)

Nam Y. Huh