Minnesota has identified 89 "breakthrough" cases of COVID-19 in which people contracted the infectious disease after being fully vaccinated.
None of these cases are among Minnesota's 6,798 COVID-19 deaths, including nine deaths reported Wednesday, and doctors said even those that were hospitalized had milder illness.
While he didn't have trend data yet, Dr. Andrew Olson said, "It's more than an anecdotal observation at this point" that the breakthrough cases treated at M Health Fairview hospitals in the Twin Cities area have had better outcomes.
The state on Wednesday reported that 1,454,834 people 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 Minnesotas are considered fully vaccinated, which means it has been 14 days since their final doses. State infectious disease director Kris Ehresmann said the fraction of fully vaccinated people who contracted breakthrough infections was expected, even with clinical trials suggesting 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," she said. "Remember, a 95% effective vaccine still means we could expect to see infections in around five of every 100 people who get the vaccine."
The state is nonetheless conducting a review of 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 specific lot was tainted.
State health officials interviewed 72 of the 89 patients and found that 30 had symptomatic COVID-19.
Overall, diagnostic testing has identified 508,541 infections in Minnesota with the novel SARS-CoV-2 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 vs. 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 over the past month in Minnesota, where 93 intensive care beds were filled on 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 activities in Carver County.
Genomic sequencing of a sampling of COVID-19 cases in Minnesota has found 479 infections with the B.1.1.7 variant.
Of cases with identified transmission sources, only 15% involved travel, meaning the virus is "widespread" and passing from person to person in Minnesota, Lynfield said.
Limited COVID-19 vaccine supplies remain prioritized in Minnesota for senior citizens, long-term care facility residents, health care workers, educators and non-elderly adults with qualifying health conditions or high-risk occupations. Those groups encompass roughly 3.5 million people.
Gov. Tim Walz is expected later this week to announce a timetable to expand eligibility to others in Minnesota. President Joe Biden has challenged states to make everyone eligible for vaccine by May.
The state is close to one incremental goal of providing vaccine to 80% of senior citizens, who have suffered 89% of Minnesota's COVID-19 deaths — including eight of the nine deaths reported Wednesday.
Jeremy Olson • 612-673-7744