Minnesota identified another 2,895 coronavirus infections among fully vaccinated people over the past week, according to new state data reported Monday, raising the total identified breakthrough infections in the state to 12,559.

Breakthrough infections have now been identified in 0.42% of the more than 3 million fully vaccinated Minnesotans — an increase from early July when they were only found in 0.11% of fully vaccinated individuals. State health officials said some increase was expected as Minnesota’s vaccination rate has increased, but that the shots continue to provide strong protection against severe cases of COVID-19 that result in hospitalizations and deaths.

The breakthrough infections included 810 people who were hospitalized, or 0.027% of fully vaccinated Minnesotans. Many of the hospitalizations involved people who were admitted for other purposes and had asymptomatic coronavirus infections identified through routine screening. Eighty fully vaccinated people have died from COVID-19 in Minnesota.

The increase comes amid a new COVID-19 wave fueled by a highly infectious delta coronavirus variant. The number of COVID-19 hospitalizations in Minnesota reached 591 on Friday.

The state also reported an increase in the positivity rate of diagnostic testing to 6.3% — up from a low of 1.1% on June 28. The addition on Monday of six COVID-19 deaths and 1,918 coronavirus infections raised Minnesota’s totals in the pandemic to 7,805 deaths and 646,094 infections.

While hospitalization numbers remain well below the peaks in prior COVID-19 waves of 1,864 on Nov. 29, and 699 on April 14, state hospital leaders said that staffed bed space is in short supply. Trauma cases, scheduled surgeries, strokes and an unexpected summer surge of respiratory syncytial virus (RSV) have combined to add pressure on the state’s hospitals, which on Monday reported a 94% occupancy rate in their intensive care units.

Immunization levels have improved ahead of the start of the school year — with 70.3% of eligible people 12 and older receiving at least first doses of COVID-19 vaccine in Minnesota. More than 92% of Minnesota’s senior citizens have been vaccinated — a vulnerable group that has suffered 87% of Minnesota’s COVID-19 deaths. The first-dose vaccination rate has risen above 50% for the 12 to 15 age group.

The discovery of 2,895 more breakthrough infections came in the same seven-day period in which Minnesota reported another 10,872 total coronavirus infections in vaccinated and unvaccinated individuals. State health officials said those numbers can’t be accurately compared, though, because some of the infections in both tallies occurred in earlier weeks and were only verified in the past week.

A group of researchers at several U.S. sites, including St. Luke’s in Duluth, have been tracking vaccine effectiveness in hospital workers and first-responders who received some of the first doses of COVID-19 vaccine after they became available in December 2020. The researchers reported last week that vaccine effectiveness at preventing infection remained strong at 80% — but had declined from 91% to 66% with the emergence of the delta variant.

The researchers said that the delta variant or waning immunity from initial vaccine doses could be responsible. Mayo Clinic researchers had reached similar findings earlier this month about waning protection from coronavirus infection, but they also found that the vaccines were strongly protective against severe illness and hospitalization — which is what federal regulators approved them for in the first place.

Federal health officials are planning to make booster doses of the Pfizer and Moderna COVID-19 vaccines widely available as early as Sept. 20.

Jeremy Olson • 612-673-7744