Gov. Tim Walz on Friday will announce looser restrictions on group events in Minnesota, despite a sports-related COVID-19 outbreak in Carver County and the state's first known infection involving a variant found in South Africa.

The governor on Thursday called the switch "probably our biggest turn" in response to improving statewide pandemic indicators, and he hinted that it could permit everything from high school proms to live Minnesota Twins baseball.

"Unless we see the variants come roaring back and something goes terribly wrong, I think those things will happen," Walz said after a speech at Robbinsdale Armstrong High School to advocate for a summer learning funding plan.

Variants are concerning because they appear to be more infectious than initial forms of the coronavirus that causes COVID-19, and it's unclear how well the new vaccines work against them.

The case of the South African variant, known as B.1.351, involved a Twin Cities resident in their 40s who had been in contact with an international traveler who may have carried the virus. Genomic sequencing confirmed the variant Wednesday after the patient fell ill on Jan. 24.

"The fewer people who get COVID-19, the fewer opportunities the virus has to mutate," said Dr. Ruth Lynfield, state epidemiologist. "The good news is that we can slow that process by wearing masks, keeping social distance, staying home when sick and getting tested when appropriate."

Minnesota earlier this year also reported the nation's first two cases of a P.1 variant found in Brazil and is nearing 200 cases of the B.1.1.7 variant found in England.

The Carver cluster related to sporting activities has reached 119 cases. Genomic sequencing of 29 samples from infected patients found the same B.1.1.7 variant, which caused a surge of cases in England late last year and prompted school closures in that country.

"We don't want to do that here," said Dan Huff, assistant commissioner of the Minnesota Department of Health. "We need our kids in school, because that's where they belong. We need our kids in sports, because that's where they belong. That's why we have to stop the virus everywhere we can, and we have a chance still to do that in Minnesota. It got out of hand in the U.K."

Huff spoke Thursday at a new pop-up testing site in Chanhassen and said that athletes across Minnesota are advised to seek testing weekly and three days before a match or game to avoid spreading the virus across communities.

State health officials hope aggressive testing and contact tracing of infections can halt or slow the Carver outbreak, while vaccination statewide protects more people.

The variants come amid otherwise stable indicators of pandemic activity in Minnesota, where the 3.5% positivity rate of diagnostic testing is below a 5% caution threshold.

Walz did not provide further details of his plan but said, "We're at a point where we have not been since this thing started, and [the announcement] will start to give guidance on larger gatherings starting as early as April."

The state on Thursday reported that 1,129,967 people have received COVID-19 vaccine, and that 642,701 have completed the series either by receiving two doses of the Pfizer or Moderna versions, or one dose of the new Johnson & Johnson version.

Minnesota on Thursday achieved an interim goal of providing vaccine to 70% of the state's senior citizens, who were prioritized for initial doses along with health care workers, long-term care facility residents and educators.

The state earlier this week expanded eligibility to about 1.8 million adults with chronic conditions or in key front-line occupations that increase their infection risks.

New Mayo Clinic research underscored the potential for vaccine to not only protect individuals but slow the spread of the virus. Clinical trials of the three vaccines primarily examined their ability to prevent symptomatic illnesses, hospitalizations and deaths, and didn't focus on whether they prevented asymptomatic cases — which can occur in as many as half of infections.

Mayo compared its patients who received routine testing before surgeries and procedures this winter by whether they had received COVID-19 vaccine. They found a risk-adjusted 80% reduction in positive COVID-19 tests in asymptomatic patients who had received two doses of the Pfizer vaccine.

Preventing asymptomatic COVID-19 is important, because then these people "are going to be less likely to serve as a source of infection for others," said Dr. Aaron Tande, a Mayo infectious disease specialist and a leader of the study. "And that is going to help to bring about the end of this pandemic."

While preliminary evidence suggests the vaccines work against the B.1.1.7 variant, it's unclear how well they all work against the South African variant and the P.1 variant "wreaking havoc" in Brazil, said Michael Osterholm of the University of Minnesota's Center for Infectious Disease Research and Policy.

"You have to start raising the question: What happens if it continues to spread like this?" said Osterholm, who likened the emergence of the variants to a new pandemic.

The Minnesota Department of Health on Thursday reported 19 more COVID-19 deaths and 1,096 known infections, raising its pandemic totals to 6,724 deaths and 494,106 infections.

The Carver cluster involves infections that occurred among players of different teams and at events after games and practices. The outbreak has involved at least nine schools, three community sports facilities, two sports clubs, and one child-care facility.

Huff said vaccine effectiveness should encourage people to stick with mask-wearing and social distancing a little longer until their turn comes up for the shot.

"Minnesotans know better than anyone else what it's like to lose a game in the fourth quarter," he said. "Let's not let that happen here."

Staff writer Briana Bierschbach contributed to this report.