For many weeks, declining cases and hospitalizations have offered hope ahead of the holiday season, when Americans travel and spend more time indoors, but progress has stalled recently, with cases rising or plateauing in more than 20 states.

In fact, the country’s daily average of cases has hovered around 72,000 infections for the past two weeks as outbreaks smolder, particularly in the northern half of the country. About 40,000 people are in the hospital with COVID-19, under half of the peak in early September.

The Mountain West — where vaccination coverage tends to be lower — is the worst off, especially Colorado, Wyoming and Montana. Parts of the Southwest and Midwest are also trying to control an uptick. Even some of the heavily vaccinated Northeast has been dealing with increases during the fall.

Modeling suggests that cases will likely stay high through the holiday season but will not accelerate into a new nationwide surge as occurred last year, says Dr. David Rubin, who leads the COVID-19 modeling group at Children’s Hospital of Philadelphia.