State officials urged more Minnesotans to get vaccinated against COVID-19 in response to an uptick in pandemic activity, including a rise in hospitalizations, that is being fueled by the more infectious delta variant of the coronavirus.

"It's really a new thing that we're dealing with — not the same old COVID that you think of from a year ago," state infectious disease director Kris Ehresmann said Monday, linking the variant first identified in India to 75% of new infections in Minnesota.

While 66.5% of eligible Minnesotans 12 and older have received at least a first dose of COVID-19 vaccine, Ehresmann said that has left gaps in the state where the virus has spread and caused more severe illness. The 153 COVID-19 hospitalizations reported Monday were an increase from 90 two weeks ago, and Ehresmann said almost all involved unvaccinated individuals.

"There's not a magic number" of vaccinations that will shield the state, she said. "It's just that where we are at is not sufficient at this point."

Minnesota has one of the lowest new infection rates in the U.S. right now.

Even a rise in the positivity rate of COVID-19 diagnostic testing from 1.1% in late June to 2.3% still has the state below its 5% caution threshold for widespread viral transmission.

However, on Monday the state reported 424 more coronavirus infections and three more COVID-19 deaths, raising its pandemic totals to 609,810 infections and 7,653 deaths, and health officials expressed concerns that delta-driven outbreaks in other states could fuel a resurgence in Minnesota.

Ehresmann said an outbreak in Provincetown, Mass., has spread the virus among vacationers from across the U.S., and that any Minnesota travelers to that destination should seek testing even if vaccinated.

Mayo Clinic was among the first organizations in Minnesota on Monday to publicly announce a vaccine requirement for its workers in response to the variant threat. California and New York City similarly issued mandates for government workers to get vaccinated or regularly tested, and the U.S. Department of Veterans Affairs on Monday required shots for all medical personnel, including at Minnesota hospitals and clinics.

Mayo's campus in Jacksonville, Fla., is on track for its worst surge of COVID-19 patients in the pandemic, and Florida's rate of fully vaccinated individuals isn't that much lower than Minnesota's rate, said Curtis Storlie, the architect of Mayo's COVID-19 predictive modeling.

Mayo's 14-day forecast for Minnesota predicts a rise in Minnesota's daily infection rate from 5 per 100,000 people to 9.

Minnesota "could be in for a bumpy ride this fall, especially in certain low vaccination pockets, Storlie said.

First-dose vaccination rates among people 12 and older range from 41% in northwestern Clearwater County to 81% in northeastern Cook County.

State Health Commissioner Jan Malcolm said she is tracking mandates by health care providers and governments in other states but has no plans for similar action yet involving Minnesota government employees. Government officials said Monday that vaccine mandates are not under consideration in Minneapolis, St. Paul, Duluth, Rochester or Hennepin County.

Mayo is requiring all employees to get shots or go through a "declination process" by Sept. 17.

Workers who remain unvaccinated must complete education modules about the vaccine and will be required to wear masks and maintain distance from co-workers when on campus.

"Our patients expect to be safe when they come to Mayo Clinic, and we need to do everything we can to protect everybody," Dr. Gianrico Farrugia, Mayo's chief executive, said in a statement.

Sioux Falls-based Sanford Health last week announced it would require shots for medical and long-term care workers by Nov. 1 while allowing certain exemptions for medical or religious reasons.

Declining transmission levels in May prompted Gov. Tim Walz to eliminate Minnesota's mask-wearing mandate, social distancing restrictions and capacity restrictions in businesses, restaurants and social gatherings that were designed to limit viral transmission.

The governor then surrendered the emergency powers granted by the Legislature that gave him the authority to issue such protections.

Walz said Monday that he is not considering calling another state of emergency for all of Minnesota in response to the delta variant.

"We're not there yet," the governor said, but noted that officials are talking about a regional approach to address the pandemic as well as planning for schools in the fall.

Bloomington-based HealthPartners this week urged parents to seek shots for eligible children — with the two-dose Pfizer vaccine being the only one approved for people 12 to 17. Pfizer doses are given three weeks apart, and then it takes two weeks after the second shot to be fully protected, said Dr. Andrea Singh, chairwoman of pediatrics for Park Nicollet and a co-leader of HealthPartners Children's Health Initiative. That means students wanting full protection by the traditional start of the K-12 school year need to get first doses this week.

"I heard from a lot of parents at the beginning of the summer that they did want their children to get the vaccine if eligible by the time that school is starting," she said. "This is the week."

Minnesota's first-dose vaccination rate is lowest in people 12 to 15 at 40%, but increases with age to 58% in people 18 to 49 and 91% in the people 65 and older who are at greatest risk for severe COVID-19 illness and death.

The state has found 3,886 infections in more than 3 million fully vaccinated Minnesotans — a breakthrough rate of 0.1% that health officials believe is further proof that the vaccine is protective. The breakthrough infections include 53 people who died of COVID-19 at a median age of 77.

Genomic sequencing of a small sampling of positive specimens has identified 268 infections involving the delta variant. While more infections have been found involving other variants — including the alpha variant that fueled this spring's outbreak — Ehresmann said the rate of growth is cause for concern.

"This particular variant has gone from less than 1% [of new infections] to over 75% in a matter of weeks," she said.

Ehresmann said efforts to increase vaccination opportunities in Minnesota have included moving doses to locations that need them before they reach expiration dates.

Roughly 7,000 doses of the single-dose Johnson & Johnson vaccine were moved to different clinics in Minnesota over the past month to prevent waste.

Staff writers Glenn Howatt, Jessie Van Berkel and Christopher Snowbeck contributed to this report.

Jeremy Olson • 612-673-7744