COVID-19 hospitalizations in Minnesota dropped below 500 this weekend, the latest sign of pandemic progress as the state prepares to remove all social distancing and capacity restrictions at month's end.

The 481 inpatient beds filled with COVID-19 cases in Minnesota on Sunday represented a 31% decline from the 699 hospitalizations on April 14.

The latest total more than doubles the 210 COVID-19 hospitalizations on March 6, though. Minnesota on Monday also reported a slight increase to 5.9% in the positivity rate of diagnostic testing for infections with the coronavirus that causes COVID-19.

Dr. Frank Rhame, a virologist for Minneapolis-based Allina Health, said the persistent amount of viral transmission troubles him because it could reflect the emergence of more infectious variants that could undermine progress.

"I'm nervous," he said. "This is a nasty bug."

The majority of new infections in Minnesota are linked to the B.1.1.7 variant first found in England, but more community transmission has been identified of concerning variants found in Brazil and South Africa as well.

The planned rollback of restrictions on May 28 is not based on the state's current level of pandemic activity — Minnesota had one of the highest new case rates in the U.S. last week — but on the presumption of continued declines in infections this month and increases in vaccinations.

More than 60% of eligible people 16 and older have received at least a first dose of COVID-19 vaccine in Minnesota, which ranks among the fastest states for administration of available doses.

A total of more than 2.6 million vaccine recipients leaves Minnesota 426,251 shots short of a new target goal of 70%. Gov. Tim Walz pledged last week to end the state's indoor public mask-wearing mandate on July 1 or sooner if Minnesota reaches that goal.

The universe of Minnesotans eligible for vaccine increased Monday when the U.S. Food and Drug Administration authorized the use of Pfizer COVID-19 vaccine in people 12 to 15 years old. There are an estimated 283,405 Minnesotans in that age range. However, the state will continue to use the existing pool of Minnesotans 16 and older for the 70% vaccination target that would end the mask mandate.

Rhame urged even more people to seek vaccine and warned that 70% is only an incremental goal. At one point, he noted that Walz and state and federal health leaders set a vaccination target of 80% because they believed that would be enough to stifle spread of the virus.

The spread of more infectious variants means that more people need to be vaccinated, he said. "The threshold for community immunity is dependent on the transmissibility [of the virus]. So if anything that threshold should have gone up, not down."

More than 2.1 million people have completed the one-dose series of Johnson & Johnson vaccine or two-dose series of Moderna or Pfizer vaccines in Minnesota. People are considered fully vaccinated 14 days after their final dose.

The state on Monday reported no COVID-19 deaths but 1,191 diagnosed SARS-CoV-2 infections — changing Minnesota's pandemic totals to 7,231 deaths and 588,952 infections.

The number of COVID-19 deaths had been rising in late April and early May, but not at the same rate as infections and hospitalizations in this spring's third COVID-19 wave. Health officials are hopeful that Minnesota's vaccination progress has reduced the death toll from the latest wave.

Nearly 88% of Minnesota's senior citizens have received COVID-19 vaccine — having been prioritized for doses earlier this winter because they have suffered 88% of the state's COVID-19 deaths. However, seniors have made up 73% of the COVID-19 deaths reported by the state since April 1 and only 62% so far this month.

Mask-wearing is still recommended as a protective strategy by state health officials, though it is no longer required outdoors in Minnesota except in certain occupational situations and at entertainment venues hosting more than 500 people.

Social distancing, washing hands and staying home when sick are other strategies that can reduce the risks of viral transmission.

Jeremy Olson • 612-673-7744