More than 1 million Minnesotans have now received at least one dose of vaccine protection against COVID-19, according to state Health Department figures released Saturday.

Gov. Tim Walz marked the milestone with a visit to the Mall of America, where retail space once occupied by Bloomingdale's serves as a pop-up vaccination center primarily for educators.

Walz said that about 55% of teachers and child care workers across the state have now received at least one shot of vaccine.

The governor voiced optimism about the growing number of Minnesotans who have been vaccinated, even as he acknowledged concern over the spread in the state of a more contagious version of the virus. On Friday, the state Department of Health announced clusters of cases in Carver County caused by the variant known as B.1.1.7, which spreads more easily and could cause more severe illness.

"We'll keep an eye on it," Walz said. "But at this time, I still remain very optimistic for our potential to keep moving forward."

Saturday's data release showed the statewide tally for people who have received at least one vaccine dose rose by 40,493, for a total of 1,016,274 people. That's 18.3% of the state's population, according to Star Tribune estimates, up from about 15% the previous Saturday.

The Health Department says 543,696 Minnesotans have completed the two-dose vaccine series, up from last Saturday's count of 430,819. Vaccination figures could understate the total for doses administered due to reporting delays.

Minnesota on Saturday reported 975 new coronavirus infections and 12 more deaths linked to COVID-19.

The latest numbers mean the seven-day rolling average for net case increases is now about 761 per day, which is down from last Saturday's comparable figure of about 805, according to the Star Tribune's coronavirus tracker.

When infections surged in November, the state at one point averaged more than 7,000 new cases per day.

Residents of long-term care and assisted-living facilities accounted for two of the newly announced deaths. Minnesota has reported 489,116 positive cases, 25,976 hospitalizations and 6,546 deaths since detecting its first virus infection on March 6, 2020.

Walz called it "almost unimaginable" to reflect on all the deaths and illnesses of the past year. The vaccination center at Mall of America was an apt location to mark the date, he added, since it showcased the shopping icon's commitment to health and safety even as the pandemic has delivered a severe economic hit to the retail, hospitality and entertainment sectors.

State residents must continue to wear masks, maintain distance and observe other health measures to control spread of the virus that causes COVID-19, Walz said. But, he added, "The opportunity for us to start looking towards an — I just have to say it — incredibly great spring and summer is right around the corner."

Saturday's one-day count of 975 new cases came on a volume of 32,076 newly completed tests, meaning the share of tests coming back positive was again lower than the state's "caution" level of 5%. The low positivity rate and the expected growth in the vaccine supply are encouraging signs, Walz said.

Health Department figures on Saturday showed a total of 1,561,329 vaccine doses administered, up from last Saturday's count of 1,269,572 total doses.

The vaccination center at the Mall of America opened Feb. 27 and was approaching 15,000 doses administered, said Jill Renslow, the mall's executive vice president for business development.

Health care workers from Minneapolis-based Homeland Health Specialists administered vaccine at 22 individual stations Saturday.

They've been providing anywhere from 1,200 to 2,200 shots during each day of operation, said Abhi Andley, the company's president and chief executive.

During the governor's visit, there was no waiting line for those seeking shots.

Janet Dray, 68, of Minneapolis, was among three dozen people who sat in an observation area after being vaccinated. Dray is not a teacher, but signed up for the vaccine through the state's Vaccine Connector service and got a message Friday that she could schedule an appointment.

"I'm super happy to be here," said Dray. "It takes the level of stress just down a little bit."

The Star Tribune's tracker showed 38 new hospital admissions reported on Saturday, which continued a recent trend of relatively low figures. One-day admission counts exceeded 300 on some days in late November, when hospitals were severely taxed.

Numbers released Saturday show health care workers have accounted for 37,982 positive cases. More than 475,000 people who were infected no longer need to be isolated.

COVID-19 is a respiratory ailment that poses the greatest risk of serious illness in those 65 and older, residents of long-term care facilities and people with underlying medical conditions. The disease is caused by a coronavirus that surfaced in late 2019.