Maine reported the biggest single-day total of new COVID-19 cases in four months Wednesday, and hospitalizations increased to their highest levels since winter.

In addition to the 433 new cases, two more people died.

With Wednesday’s total, the seven-day daily case average increased to 283, up from 173 two weeks ago and from 79 cases on average this time last month, according to data tracked by the Maine Center for Disease Control and Prevention. The seven-day positivity rate, or the percent of all tests that come back positive, increased to 4.8 percent.

CDC spokesman Robert Long said this week that the state has been receiving a high volume of test results each day and hasn’t been able to process them all in a 24-hour period. That means each daily count might reflect positive tests over multiple days.

All 16 Maine counties are seeing either substantial or high virus transmission, defined by the U.S. CDC as at least 50 or 100 cases, respectively, per 100,000 people over the last seven days. Per CDC guidance, masks are recommended in all indoor public settings in Maine regardless of vaccination status.

Piscataquis County, which has the second lowest vaccination rate of any county, added 37 new cases Wednesday and its seven-day case rate of 399 per 100,000 people is the state’s highest. Aroostook County, which also has a vaccination rate well below the state average, added 69 cases Wednesday, and its seven-day rate increased to 310 per 100,000 people. Penobscot County, which also has been a hotspot of late, reported 91 new cases, the most of any county.

Overall, there have been 76,289 confirmed or probable cases of COVID-19 and 934 deaths since the pandemic reached Maine in March 2020. Both remain among the lowest per capita of any state even with the recent surge, which is crippling every other state as well.

The number of people hospitalized with COVID-19 increased to 150 on Wednesday – the highest total since Feb. 4. Of those, 66 are in critical care and 26 are on ventilators. In less than a month, total hospitalizations have tripled and the number of people in critical care has reached levels not seen since winter.

Hospitalizations often lag behind case spikes by at least two weeks, so there is growing concern that things could get worse, although the overwhelming majority of individuals being hospitalized recently are unvaccinated.

For instance, of the 47 patients being treated for COVID-19 in the Northern Light Health network, which includes Bangor’s Eastern Maine Medical Center, 44 are unvaccinated. Of the 25 who are in critical care, 24 are unvaccinated.

“Vaccinations can turn COVID-19 into a disease we can manage,” said Dr. James Jarvis, COVID-19 incident commander for Northern Light Health.

Of the 50 people hospitalized for COVID-19 in the MaineHealth network on Wednesday, 35 are unvaccinated, or 70 percent, spokesman John Porter said. That number fluctuates, however, and has been as high as 90 percent or more. Although he couldn’t provide the number of critical care patients who are unvaccinated, he said that as of last week, all of them were.

Jarvis said Northern Light staff has been planning for the possibility of needing to erect a temporary facility if demand outweighs capacity, but he hopes it doesn’t come to that. In the meantime, staff at all network hospitals communicate regularly and shift patients as needed to meet demands. On rare occasions recently, he said, staff has delayed non-urgent medical procedures.

“But it is concerning. There are very few open beds available to us,” Jarvis said, adding that the shortage could affect others who might need to be hospitalized for a heart attack, an accident or a childbirth.

As for vaccinations, the state continues to see a steady increase in daily doses administered over the last few weeks, likely in response to both the delta variant and an increasing number of vaccine mandates. As of Wednesday, 845,675 final doses had been administered, accounting for 62.9 percent of all residents and 71.4 percent of those 12 and older who are eligible.

Over the last two weeks, the number of daily doses administered per day has increased by 30 percent, according to the Maine CDC.

Gaps persist, however, among young Mainers and residents of rural counties who have yet to get vaccinated.

For instance, only five counties have vaccination rates above the statewide rate, led by Cumberland County at 74 percent. Four counties – Somerset, Piscataquis, Franklin and Oxford – have rates below 54 percent, more than 20 percentage points behind Cumberland County.

The difference is even more stark among younger adults. For those between the ages of 20-39, the rate in Cumberland County is only slightly higher than the county’s overall rate, 75 percent. All but one other county have rates below 60 percent among that age group.

In Somerset County, just 38 percent of 20-39 year olds are fully vaccinated, and in Piscataquis County the rate is only 40 percent.

The U.S. CDC on Tuesday asked unvaccinated Americans not to travel during the upcoming Labor Day weekend. New cases are averaging about 160,000 per day in the U.S., the highest since January.

Maine is now one full month away from a deadline for most health care workers to be fully vaccinated. Those who are not have until Sept. 17 to get a second dose of Pfizer or Moderna vaccine or the one-dose Johnson & Johnson vaccine.

There has been some pushback to the mandate, including concerns about the impact on an already tenuous workforce, but it remains to be seen how many employees might leave their jobs, or be terminated if they fail to comply.

Paul Bolin, chief human resources officer for Northern Light Health, said 88 percent of employees are now fully vaccinated. As of Wednesday, he said, 23 of the network’s approximately 12,000 staff members have resigned because of the mandate. Bolin did not say where those employees worked, citing privacy reasons.

“We continue to work with staff to address any hesitancy or concern,” he said, adding that people who remain unvaccinated are being removed from schedules for next month.