A frenzy for COVID-19 vaccine emerged Friday morning even before Gov. Tim Walz announced an expansion making everyone 16 and older eligible for shots starting Tuesday.

Around 10,000 people overnight joined the Minneapolis Vaccine Hunters Facebook group, where moderator Maura Caldwell urged patience because it wasn't clear if pharmacy and clinic providers would honor appointments booked today for newly eligible recipients.

"This doesn't mean everyone owes you vaccine on Tuesday," she said, "because that's not how this works."

The announcement nonetheless means an aggressive expansion in Minnesota, even though the state has yet to vaccinate as many as 2 million people who were prioritized for their risks of infection or severe COVID-19 illness. Walz on Friday said the move was motivated by concern over rising pandemic activity due to more infectious viral variants and confidence in increasing weekly supplies of federally controlled vaccine.

"We have to outrun those variants," Walz said. "We have to stop the spread that's out there, and Minnesota is one of the states where it is gaining, but the good news is we are countering it with an aggressive vaccine effort."

The governor is slated to receive the vaccine next week, having been quarantined through Thursday because of contact with a staffer who tested positive for the coronavirus that causes COVID-19.

Walz said he was influenced by rural providers who are in a position to expand eligibility, as well as Minnesota's progress. The state has risen from among the worst in the nation in January to first in March in a key measure of vaccine efficiency — with 89% of its available shots administered.

Minnesota also has reached a key goal of providing vaccine to 80% of senior citizens, who have suffered 89% of the state's 6,821 COVID-19 deaths. That includes seven deaths reported Friday along with 1,714 more diagnosed infections — which raised Minnesota's case count to 512,097.

The move catches Minnesota up with states such as Alaska, Arizona, Mississippi, Utah and West Virginia, which had already expanded access, but in some ways it just makes the long waiting line longer.

While 1,510,237 people have received at least first doses, that leaves 2 million people unvaccinated from the current eligibility group that includes seniors, educators, long-term care residents, health care workers and non-elderly adults with qualifying medical conditions or high-risk occupations.

The expansion adds 900,000 people 16 and older who are at lower risk of severe COVID-19 outcomes, including healthy adults who have been anxiously waiting their turn and teenagers who are looking for the security of vaccine to protect them in classes and during sports.

Walz challenged Minnesota to be the first state to vaccinate 80% of its eligible population — a number that could achieve herd immunity and stifle the spread of the virus. Needier people will be prioritized under the new system, which Walz likened to a multilane highway with seniors and others vulnerable to COVID-19 in the fast lane.

"If no one is in that lane, our providers will move to the next lane," said Walz, encouraging people to sign up on the state Vaccine Connector to be notified when vaccine is available.

Increased supplies will help but won't cover the demand. Minnesota is expecting its weekly supply of 185,000 first doses — including those going to chain pharmacies under a federal contract — to increase to 304,000 doses in early April.

Kathryn Klibanoff of Minneapolis and her husband have received first doses of the Moderna vaccine already, but they will be aggressively seeking appointments starting Tuesday for their 16-year-old daughter. Vaccination would ease her anxiety about going back to in-person classes and reduce her infection risk while playing Ultimate Frisbee.

"She's really nervous about being in an environment 3 feet apart from lots of teenagers who may or may not have the best COVID hygiene," her mother said. "So she is anxious to be vaccinated."

The two-dose Pfizer vaccine is available to people ages 16 and 17, while the age limit for the two-dose Moderna and single-dose Johnson & Johnson versions is 18.

More infectious variants of SARS-CoV-2 appear responsible for increased pandemic activity in Minnesota and an outbreak centered on youth sports in suburban Carver County. The positivity rate of COVID-19 testing rose from 3.5 to 4.7% this month.

The 357 Minnesota hospital beds filled with COVID-19 patients on Thursday was the highest count since Feb. 6 — though below the peak of 1,864 during the last pandemic wave.

"We are in a race between the variants and the vaccine, and we must remain vigilant and work together so the vaccines win," said state Health Commissioner Jan Malcolm.

While large providers such as M Health Fairview, Mayo, Allina and HealthPartners indicated that they would continue to invite and prioritize higher-risk patients for vaccination, Malcolm said retail pharmacies might not be so restrictive in their scheduling. The state will be advising larger chains on where to distribute more of their doses and appointments based on any underserved areas, she said.

Fairview will be expanding its vaccine priority Tuesday only to people 50 and older, people 16 or older with qualifying health conditions, and underserved minorities. However, Dr. Abe Jacob, chief quality officer, said the flexibility will help to deal with practical situations, such as also vaccinating a 61-year-old spouse who drove a 67-year-old in for a vaccine appointment.

"Now we can vaccinate both," he said, "and that makes sense to us."

Problems with younger people jumping ahead in line could persist for about four weeks, he said, but will eventually ease as vaccine supplies increase.

Promotional campaigns ranging from social media messages to celebrity endorsements are likely to appear soon now that everyone has access.

Some health care providers lobbied against the expansion, which could emphasize speedy vaccinations to all over the slower process of identifying remaining high-risk individuals and getting them scheduled.

"Opening up vaccine to everyone is almost a sign of defeat" toward vaccinating those individuals, said Michael Osterholm of the University of Minnesota's Center for Infectious Disease Research and Policy, "because what's happened is the political pressure to get all these vaccine doses administered is so high that you don't want to hold them for three days or more."

Vaccine access had been proportionally greater in some rural ares that got further ahead in immunizing priority groups. While many urban providers are booked solid for appointments, some rural pharmacies and providers were starting to see appointments going unfilled.

"Rural vaccinators are excited for the opportunity to move into the next tier as they had begun to exhaust the eligible populations in their communities," said Adam Shadiow, an EMS leader and part of the Northeast Healthcare Preparedness Coalition. "Until the eligibility announcement was released by the governor's office yesterday, many of our providers had declined a shipment of vaccine to their community for next week."

Staff writers Briana Bierschbach and Glenn Howatt contributed to this report.

Jeremy Olson • 612-673-7744

Correction: Previous versions of this story had an incorrect number for the Minnesotans added to the pool of state residents vying to secure a shot of virus protection. It is 900,000 more.