Minnesota health officials on Wednesday urged renewed vigilance against COVID-19, looking back at November, this year's deadliest pandemic month, and ahead toward the threat of the new omicron variant.

State Health Commissioner Jan Malcolm said Minnesota has strengths in its high vaccination and booster rates, increasing supply of monoclonal antibody therapies and surveillance system to detect variants. But she worried that Minnesotans after 20 months of the pandemic have "gotten a little bit lax" on prevention efforts such as mask-wearing.

"All viruses mutate all the time and each new infection in a person is a new opportunity for the virus to change," she said. "That is just one of many reasons why it's so important here in Minnesota and all around the world that we do what we can to limit the rate of those new infections."

Minnesota reached a 2021 record of 628 COVID-19 deaths in November with the state adding 100 deaths Wednesday to catch up on reporting after the holiday. That exceeded the 575 COVID-19 deaths in October but remains behind the 1,503 deaths in November 2020 during the most severe pandemic wave.

Vaccines weren't available until December 2020 and that explains the difference in deaths, even though hospitalizations were comparable over the last two Novembers, said state infectious disease director Kris Ehresmann.

"We have 92% of our 65+ population completely vaccinated," she said in an e-mail. "And this is the group most susceptible to dying from COVID-19. So vaccination has taken a bite out of the deaths we are seeing in November."

COVID-19 hospitalizations in Minnesota increased to 1,562 on Tuesday, bringing the state closer to the record of 1,864 hospitalizations on Nov. 29 last year. Vaccinated patients are more common but unvaccinated patients still take up the majority of beds, even though they make up only one-third of Minnesota's population.

Minneapolis-based Allina Health reported that 298 of 397 of its COVID-19 hospitalizations on Monday involved unvaccinated patients. Among 58 COVID-19 patients on ventilators, 53 were unvaccinated.

The state on Wednesday announced an expansion of monoclonal antibody infusions, which are provided early in the course of COVID-19 to prevent severe illness and hospitalization. Infusions have already increased from 2,000 per week this fall to 3,000 in the week ending Nov. 24.

Sixteen workers from the Federal Emergency Management Agency have been dispatched to Minnesota to expand vaccination capacity at the state's Mall of America site and monoclonal antibody infusion opportunities.

Minnesota has reported 9,482 total COVID-19 deaths and 915,942 coronavirus infections, including 3,580 infections that were added Wednesday. While 86% of Minnesota's COVID-19 deaths have been among seniors, Ehresmann said the average age has declined in the latest wave. Wednesday's reported deaths included four people in their 40s from Anoka, Dakota, Hennepin and Stearns counties.

State leaders urged unvaccinated Minnesotans to seek shots and vaccinated adults to seek booster doses. Immunity appears to wane six months after vaccination, putting Minnesota's earliest elderly and vulnerable vaccine recipients at risk. Minnesota ranks second among states with nearly 34% of vaccinated adults receiving boosters, according to the Centers for Disease Control and Prevention.

Malcolm said much is unknown about omicron, which was labeled a variant of concern because of its rapid spread in South Africa and potential to evade immunity. The first U.S. infection with this variant was reported Wednesday in California. However, Malcolm said prevention measures are unlikely to change and that "everyone should really be masking up in indoor public settings" given the already high transmission rates with the delta variant.

Surveys showed that 79% of Minnesotans always wore masks in public in February, but that the rate declined to 22% this fall, among the lowest in the nation. Malcolm said this probably reflects exhaustion but also perhaps too much confidence in the vaccines.

"Many, many folks have been vaccinated and therefore think they don't have to worry about masking," she said. "But I think the data have gotten more and more clear that that is still really a good idea, even for vaccinated folks, given delta."

State health officials are hopeful that a decline in COVID-19 test positivity could suggest a peak in the latest wave. The state on Wednesday reported a 10.4% test positivity rate, down from a recent high of 11%.

The rate remains above Minnesota's high-risk threshold for substantial viral spread, though, and health officials said they are cautious about predicting trends until the impact of the Thanksgiving holiday becomes clearer.

While Minnesota's rate of infections held steady over the past seven days, it dropped from first to fourth among states with the highest infection rates, according to the latest CDC data. Vermont, Michigan and New Hampshire have higher rates, reflecting the latest coronavirus wave that was most severe in the South this summer but gradually moved north in the fall.