The number of people hospitalized in Maine with COVID-19 increased slightly, the state reported Sunday, as the country experiences what the White House’s top medical adviser described as a “vertical increase” of new cases.

Throughout Maine there were 340 patients hospitalized with COVID-19, up from 338 on Saturday, according to the Maine Center for Disease Control and Prevention.

Sunday’s numbers include 119 in critical care units and 57 on ventilators.

Two-thirds of all COVID-19 patients in Maine are unvaccinated, health officials say. And in critical care units nine out of 10 are unvaccinated.

White House Medical Adviser Dr. Anthony Fauci said Sunday the United States is now averaging 400,000 cases a day, with hospitalizations rising.

“We are definitely in the middle of a very severe surge and uptick in cases,” he said. “The acceleration of cases that we’ve seen is unprecedented, gone well beyond anything we’ve seen before.”

Maine counties with low vaccination rates have experienced far more COVID-19 deaths per capita than high-vaccinated counties since vaccines became widely available. A Portland Press Herald/Maine Sunday Telegram analysis found that coastal communities with a higher number of vaccinated people – Cumberland, Lincoln and Sagadahoc counties – have death rates about three times lower than the lower-vaccination counties of Somerset, Piscataquis and Franklin.

In Cumberland County, 82.02 percent of the total population is fully vaccinated, the state reported Sunday. That is the highest vaccination rate in Maine. In Somerset County, 58.11 percent of the population is fully vaccinated, the lowest rate.

Doctors see the pattern in their wards every day. Witnessing people die from what is largely a preventable disease is “just wrenching,” said Dr. Cheryl Liechty, an infectious disease physician with Maine Health’s Pen Bay Medical Center in Rockport and Waldo County General Hospital in Belfast. “It’s very clear counties that are more highly vaccinated have seen fewer deaths and fewer hospitalizations,” she said. “It’s a good way to illustrate the power of vaccines.”

While the number of patients is down from a peak of 387 on Dec. 21, the load is still high enough that it continues to strain hospital staff and resources. With the fast-spreading omicron variant infecting more people, hospitals are bracing for a possible increase in illnesses.

The state did not report new case numbers on Sunday. Since the pandemic began, there have been 146,736 confirmed or probable cases of COVID-19, and 1,531 people with the virus have died.

With the spread of the omicron variant, along with a big demand in home testing, experts say the number of cases is likely underreported. Health experts stress the public should wear masks when going into public, indoor spaces, even if fully vaccinated, because the omicron variant is far more contagious. Monday night the Portland City Council is expected to consider reinstating masking in public, indoor spaces.

Meanwhile the number of people vaccinated in Maine is rising.

The state reported Sunday that 71.36 percent of residents have been fully vaccinated, and 475,565 have been boosted. Maine children ages 5-11 who are fully vaccinated now number 28,838.