As Minnesotans celebrate summer's final holiday, daily COVID-19 deaths remain relatively low and use of hospital and ICU beds is holding steady, but doctors remain nervous that serious illnesses could quickly escalate.

People seem less fearful of COVID-19 on Labor Day weekend than they were around Memorial Day, and that's a perspective that could bring serious consequences, said Dr. John Hick, an emergency medicine physician at Hennepin Healthcare who manages the statewide health care coordination center focused on the virus.

"The question is: How bad is it going to be?" he said.

"I think there's reason for hope, and there's still a lot of reason to be concerned. The nature of this virus is that it passes through one person with no consequences and can kill the next."

Memorial Day roughly coincided with Minnesota's first peaks in deaths, hospitalizations and cases but was followed by weeks of improvement. The recent uptick in cases in the run-up to Labor Day hasn't resulted in more patients requiring hospital beds, Hick said, but whether that continues much longer is uncertain.

The big variable is what happens once schools are back in session, said Dr. Andrew P.J. Olson, one of the medical directors at M Health Fairview Bethesda Hospital.

"There will be spread that will happen in schools. We know that that will happen," Olson said. "We don't know what that will bring with respect to ... hospitalizations and mortality."

Health officials Saturday reported that four more people have died of COVID-19 in Minnesota, including three residents of long-term care or assisted living facilities. Those residents account for 1,357 deaths out of the statewide pandemic total of 1,851 deaths.

The Minnesota Department of Health reported a net increase of 914 new coronavirus infections, according to data released Saturday morning, on a volume of about 16,695 completed tests. The numbers rounded out a week when Minnesota averaged about 803 new cases per day — one of the highest figures so far during the pandemic — on roughly 16,468 tests.

Numbers released Saturday show 279 patients were hospitalized, up three from Friday's data release; 133 patients required intensive care, compared with the Friday total of 138 ICU patients. The counts have been holding steady in recent weeks and remain well below peaks in late May of more than 600 hospitalized patients and about 260 in the ICU.

Back then, hospitals had limited supplies of ICU beds and ventilators, said Dr. Mark Sannes, an infectious disease specialist with HealthPartners.

The big change since Memorial Day, Sannes said, has been improvements in long-term care facilities that have reduced the number of vulnerable residents getting sick and ultimately dying. Another factor is improved treatments in hospitals for COVID-19 patients, he said.

One marker of the change, Sannes said, is that the length of hospital stays for HealthPartners patients with COVID-19 is three full days shorter on average than it was in the spring.

State public health officials have cautioned for weeks that the growing daily tallies of new cases could eventually lead to more serious illnesses. It's a view shared by Sannes.

"We were very good at sort of staying away from each other in the early spring," he said. "I think we're starting to see the fatigue of trying to maintain social distancing and maintain vigilance around this ...

"I don't think it's just unnecessary worry right now around the case growth that we're seeing. I think it's a matter of time before that case growth translates to patients at risk."

Clinical trial for vaccine

HealthPartners runs a health insurance company, dozens of clinics and eight hospitals including Regions Hospital in St. Paul and Methodist Hospital in St. Louis Park. Last week, the nonprofit announced recruitment in Minnesota for up to 1,500 adults for a study of a coronavirus vaccine from the pharmaceutical company AstraZeneca.

The vaccine is one of several promising candidates in development that could eventually reduce the need for broad social measures to control the pandemic, Sannes said.

Flu season nears

Fall and winter typically bring flu to Minnesota, but there are encouraging signs from the southern hemisphere that it might not hit hard, Olson said. COVID-19 preventive measures such as wearing masks and washing hands could have an impact.

Even so, doctors recommend Minnesotans get flu shots. HealthPartners this week is launching for the first time drive-in vaccinations against flu at certain locations, which builds on widespread adoption of drive-in testing for the coronavirus.

A bad flu season can stretch hospital capacity even without COVID-19 patients, yet Olson said he thinks hospitals can handle whatever is coming.

"We can adapt how our system works," he said.

The impact of COVID-19 goes far beyond the health care sector. Hick said that widespread job losses and reduced incomes are just some of the factors compounding stress.

"If you're not stressed these days, you're blessed — and I want to know the secret," he said. "It's a natural for the human condition right now that we're all under a lot of stress."

COVID-19 is a viral respiratory illness caused by a new coronavirus that was found circulating late last year. Since the first case was reported in Minnesota in early March, hospital stays have been required in 6,676 cases.

People at greatest risk from COVID-19 include those 65 and older, residents of long-term care facilities and those with underlying medical conditions ranging from lung disease and serious heart conditions to obesity and diabetes.

Most patients with COVID-19 don't need to be hospitalized. The illness usually causes mild or moderate sickness; studies suggest that up to 45% of those who are infected won't have symptoms.

The state has reported 79,880 cases during the pandemic, including 71,507 people who no longer need isolation.