More than 7,000 fully vaccinated Minnesotans have suffered breakthrough corona­virus infections, but state health officials said that remains a low rate and that more immunizations are the state's best defense against the latest COVID-19 wave.

The Minnesota Department of Health on Monday reported that the 7,171 breakthrough infections make up 0.24% of fully vaccinated people. The breakthrough cases include 60 people who died of COVID-19, or 0.002% of nearly 3 million fully vaccinated Minnesotans.

The breakthrough infection rate has increased slightly, from 0.11% a month ago, but state infectious disease director Kris Ehresmann said COVID-19 vaccines continue to provide strong protection against severe illness and COVID-19 hospitalizations.

"Although we are seeing a slightly greater proportion of breakthrough cases, the vaccines are continuing to do their job," she said.

Overall, the state reported 7,734 COVID-19 deaths and 626,310 coronavirus infections, including five deaths and 1,470 infections added on Monday. COVID-19 hospitalizations increased Friday to 411 — up from 90 in mid-July — as the result of a highly transmissible delta variant of the coronavirus.

The variant caused severe and widespread outbreaks in nations such as India and England but peaked quickly. Health officials hope this shorter duration will occur again, and that Minnesota's above-average vaccination rate can lessen its impact. More than 3.2 million Minnesotans have received at least a first dose of COVID-19 vaccine — 68.9% of the state's eligible 12 and older population.

Mayo Clinic's 14-day COVID-19 forecast predicts a doubling of the infection rate in Minnesota — with widespread outbreaks in Southern states gradually spreading north — but other models offer more optimism. The CDC merges 20 COVID-19 forecasts into the Ensemble model, which last week predicted at least a temporary peak and slight decline in Minnesota's rate of infections before Sept. 1.

While a peak this month is possible, Minnesota looks a lot like Florida did five weeks ago, before its sharp surge in cases, said Curtis Storlie, a creator of the Mayo model. "Would I be shocked if we unexpectedly plateau in Minnesota? No … but the much more likely scenario is that there will be further increase from here in Minnesota for the next month or so."

State health officials remain concerned about the risk of viral transmission at large events, ranging from the Sturgis Motorcycle Rally in South Dakota last week to the Minnesota State Fair next week.

Outbreaks involving at least three infections have been identified at 13 fairs, four concerts and eight weddings in July, according to the latest state data.

"There will always be some risk at these events, so we advocate a layered approach that includes getting vaccinated," but also wearing masks in high-transmission areas and staying home when sick, Ehresmann said.

The CDC recommends masks indoors, regardless of vaccination status, in counties with substantial or high transmission rates.

In Minnesota, 79 of 87 counties fall under this guidance — including the entire Twin Cities area.

Mayo researchers encouraged more people to seek vaccine despite the release of their study showing a decline last month in the effectiveness of the Moderna and Pfizer vaccines in preventing infections — presumably because of the delta variant.

The vaccines remained strongly protective against the onset of severe illness and the need for hospitalizations, which was what federal regulators approved them for in the first place, said Dr. Andrew Badley, a co-author of the study and chairman of Mayo's COVID-19 research task force.

"It was proven to prevent severe disease, hospitalization and death," he said. "This concept of breakthrough infections has been lumped into one big group, and my view is that it's kind of misguided to do so," because it includes asymptomatic infections caught through routine screening and mild illnesses that were lessened by the vaccine.

Gov. Tim Walz on Sunday extended the state's $100 incentive program for new vaccine recipients. First-dose vaccinations have more than doubled over the past month — partly because of the incentive but also because of variant concerns and calls to immunize children 12 and older before school starts.

More than 55,000 new vaccine recipients have submitted incentive requests since Aug. 4. The extension keeps the incentive available through Aug. 22.

"With the delta variant pushing cases up across the country, including right here in Minnesota, we've entered a new phase in the battle against COVID-19," Walz said in a statement. "The vaccines are the way we fight back against the virus."

Jeremy Olson • 612-673-7744