MINNEAPOLIS — Minnesota is expected to pass a milestone this week by administering its 1 millionth dose of coronavirus vaccine, even though severe winter weather in other parts of the country is likely to disrupt supplies, Health Commissioner Jan Malcolm said Tuesday.

Meanwhile, Gov. Tim Walz plans to lay out a strategy Wednesday to bring more middle and high school students back to the classroom, said his spokesman, Teddy Tschann. About 85% of Minnesota classes from kindergarten through eighth grade now get some degree of in-person learning. The state launched an aggressive testing program for educators last month, and data from it shows that the transmission rate among teachers is only 0.37%.

Malcolm gave no specifics at her periodic briefing of what Walz might announce. The commissioner said the state is still reviewing new guidance issued Friday by the federal Centers for Disease Control and Prevention, which said in-person schooling can resume safely with masks, social distancing and other strategies, and that vaccination of teachers, while important, is not a prerequisite. The commissioner noted that Walz said Friday that he'd like to make it possible for all kids to return to school as quickly as it's safe to do so.

The Minnesota Department of Health's vaccine dashboard showed that the state's health care providers had administered a total of 927,384 vaccine doses as of Sunday. That figure covered 686,210 people who'd had at least their first doses as of Sunday, which included the 240,027 people who had completed the two-dose series. The department said that meant 12.3% of Minnesota's population had had at least one dose, with 4.3% having had both doses.

Kris Ehresmann, the department's infectious disease director, said storms in the South are delaying vaccine shipments this week, so providers are "scrambling to reschedule" appointments in response. This may affect some of the state's measures of timeliness next week, she added.

The department tracks how well providers are doing at meeting the goals of administering 90% of their doses within three says of receiving them and 100% within seven days. The dashboard shows that all but a couple major health care systems are hitting those targets.

It's too early to tell, Malcolm said, how much more vaccine Minnesota will get under plans to increase supplies that the White House announced to the country's governors Tuesday.

"But they certainly are forecasting to us that we can and should be planning for a more robust supply, she said.

Ehresmann said she expects Minnesota to get "a bit more," but said the weather will have an impact, and some of the increase may show up only on paper because each Pfizer vaccine vial is now counted as containing six doses instead of five.

The health department on Tuesday also reported 456 new coronavirus cases, with two new deaths, for totals of 474,621 cases and 6,380 deaths since the pandemic reached the state last March. Key metrics continue to decline, including the state's seven-day rolling averages for new daily cases and deaths, while the seven-day average positivity rate is down to 3.8% compared with the state's "caution level" of 5%.

Malcolm said the state is seeing "continued really encouraging progress" in cases among residents and staff in long-term care setting such as nursing homes, who were at the front of the priority line for vaccinations. Only 15 cases were reported in nursing homes, according to the latest weekly data.

The last time Minnesota saw weekly numbers that low for long-term care was last March, the commissioner said. While there's evidence that vaccines are helping, she said, staff, residents, families and public health officials also deserve credit.