Minnesota has identified 89 "breakthrough" infections of the novel coronavirus that causes COVID-19 in people who have been fully vaccinated.

None are among Minnesota's 6,798 COVID-19 deaths, including nine deaths reported Wednesday, and doctors said even those who were hospitalized after being vaccinated had milder illness.

"Yes, people get COVID, but people in general do overall better," said Dr. Andrew Olson, M Health Fairview's medical director for COVID-19 hospital medicine. "We have seen that both in patients in our system who are hospitalized and patients who are not hospitalized."

Olson's father tested positive for COVID-19 last month, a few days after receiving his first dose of vaccine.

Minnesota on Wednesday reported that 1,454,834 people in the state have received COVID-19 vaccine and 862,955 of them have completed the series by receiving two doses of the Pfizer or Moderna vaccine or one dose of Johnson & Johnson's version.

A slightly smaller number of around 800,000 Minnesotans are considered fully vaccinated. That means it has been 14 days since their final doses and the vaccine has had time to trigger an effective response by the immune system. Based on that 800,000 estimate, that would make the 89 known COVID cases equal to about 1 such instance for every 9,000 people fully vaccinated.

State infectious disease director Kris Ehresmann said the fraction of fully vaccinated people who still contract infections was expected. Clinical trials suggested the Pfizer and Moderna vaccines were 95% effective.

"We should not be fooled into seeing such a case as a reason to doubt the vaccine effectiveness," said Ehresmann, noting that the breakthrough cases represented less than one-tenth of one percent of people who have been fully vaccinated.

Out of caution, the state is reviewing the cases to see if they have anything in common, Ehresmann said. A cluster of cases vaccinated at the same site could suggest a handling problem with the vaccine, or that a lot was tainted.

State health officials interviewed 72 of the patients and found 30 had symptomatic COVID-19. Many were identified through routine testing in long-term care facilities. Of 95 COVID-19 patients admitted to M Health Fairview hospitals in the metro area Wednesday, only one had been fully vaccinated.

Olson's father, a 72-year-old semiretired pastor from northeast Iowa, isn't part of Minnesota's tally or a true "breakthrough" case as he wasn't fully vaccinated when he tested positive. His family nonetheless experienced the emotional swing from hope after vaccination to fear when the infection appeared.

"I opened up a fresh bag of coffee, you know, unsealed it," his father, Phillip Olson, said. "That usually is such a wonderful smell, and there was nothing. So I went and got tested and it came back positive."

Under his son's orders, the elder Olson had been careful to wear masks and limit social contact. He and his wife are pastors but perform services via a low-power radio transmitter that can be heard by visitors parked outside the church.

"I do part of the liturgy and sing," he said. "And I never shake hands. I wave across the street [to the churchgoers.]"

The family believes even one dose helped, because Olson has advanced prostate cancer and was at elevated risk for severe COVID-19.

"I am loathe to interpret evidence on the basis of one patient," his son said, "but I am scared to think how things would be today had my parents not gotten their vaccines."

Testing has identified 508,541 infections in Minnesota with the novel coronavirus that causes COVID-19. That includes 1,323 infections reported on Wednesday.

A more infectious viral variant known as B.1.1.7 is widespread in Minnesota, threatening to undermine the state's vaccination progress, said Dr. Ruth Lynfield, state epidemiologist. "At this point, it is a race to vaccinate more people versus the growth of variant cases."

The positivity rate of COVID-19 diagnostic testing has increased from 3.5% to 4.6% in March — reflecting a spring-break blip similar to Thanksgiving or Christmas, or a new wave driven in part by some of the more infectious variants. Hospitalizations also have increased this month in Minnesota, where 93 intensive care beds were filled Tuesday with COVID-19 patients.

While vaccine appears effective against B.1.1.7, the variant has caused new case waves in Europe as well as a local outbreak centered on youth sports in Carver County.

Genomic sequencing of a sampling of infections in Minnesota has found 479 cases of the B.1.1.7 variant.

Limited COVID-19 vaccine remains prioritized in Minnesota for senior citizens, long-term care facility residents, health care workers, educators and nonelderly adults with qualifying health conditions or high-risk occupations.

Those groups encompass roughly 3.5 million people, including adults 50 and older who live in multigenerational homes, elevating their risks for viral exposure.

Gov. Tim Walz later this week will announce a timetable to expand eligibility to others in Minnesota. President Joe Biden has challenged states to make everyone eligible for vaccine by May, and at least six, including North Dakota, will have reached that stage by March 29.

Walz has hesitated to expand eligibility when there is too little supply to serve the most at-risk people. Minnesota's weekly shipments of around 185,000 first doses, when including federal contracts for chain pharmacies, are expected to increase to 304,000 in April.

Minnesota is close to one incremental goal of providing vaccine to 80% of seniors, who have suffered 89% of Minnesota's COVID-19 deaths. The broader goal is to vaccinate 80% of the eligible population of those 16 and older. That would result in herd immunity and stifle the spread of the virus, Ehresmann said.

"Once we reach that herd immunity, the virus will not be able to find the small number of people who remain susceptible," Ehresmann said, "either because they didn't get vaccinated or because they didn't have a strong enough immune response to the vaccine."

Jeremy Olson • 612-673-7744