Gov. Tim Walz and former Gov. Tim Pawlenty received COVID-19 vaccine booster shots Tuesday to promote immunization against the pandemic.

Walz and his predecessor received single-dose Johnson & Johnson shots in March at a mass vaccination event in Eagan and received boosters — now that they are advised — at a Cub Pharmacy in north Minneapolis along with Health Commissioner Jan Malcolm.

"These vaccines are one of the primary ways out of this pandemic and we want to get out of this damn thing as soon as possible," said Pawlenty, the Republican who received his booster jab in his right arm, while Walz received it in his left arm, in a sequel to their political humor from the March event.

More than 76% of eligible Minnesotans 12 and older have received at least first doses of COVID-19 vaccine, but state health officials urged more people to get their shots and seek boosters because the number of breakthrough infections is rising amid the spread of the delta variant.

"Immunity begins to wane at about six months. It doesn't just drop off a cliff. … The booster is just going to extend that protection and strengthen it against infection, which really helps to slow the spread in our communities," said Malcolm, who received a Moderna shot.

Boosters following two doses of Pfizer and Moderna vaccines are recommended only for seniors and younger adults with underlying health conditions or jobs that increase their infection risks, but are recommended for anyone who have received J&J doses.

More than 3.6 million people in Minnesota have received COVID-19 vaccine, according to the Centers for Disease Control and Prevention, but fewer than 300,000 received the one-dose J&J vaccine.

Federal and state booster recommendations allow for mixing of vaccine types. One recent U.S. study showed that J&J recipients gained more antibodies from any boosters, but that they gained the most when receiving the Pfizer or Moderna versions.

Walz received a Moderna booster and commended Minnesota for ranking third among states in its rate of booster doses already administered.

"All three are great choices," said Walz, who made his decision after talking with his doctor and learning that a Moderna booster might give him a "broader spectrum" of protection.

Pawlenty chose a J&J booster after checking his online fantasy football score and doing a little Google research on his options. Despite vaccination hesitancy being higher among Republicans, Pawlenty said his party should be proud that the vaccines are available.

"Operation Warp Speed and the efforts … to deliver these vaccines in a timely basis was one of the most positive accomplishments in the Trump administration and in the last Republican administration," Pawlenty said. "So, for my party, I think the availability and effectiveness and safety of these vaccines should be a point of pride, not a point of skepticism."

Studies have found that vaccination doesn't prevent all infection — especially in the era of the delta variant — but remains strongly protective against severe illness, hospitalization and death.

Observational data among local hospitals has verified the trend. HealthPartners hospitals in Minnesota and western Wisconsin have hospitalized 367 COVID-19 patients in the last 30 days, and 74% were unvaccinated.

Among patients who needed ventilators to breathe, 91% were unvaccinated.

Doctors and nurses have grown frustrated watching relatively young and healthy patients struggle with severe COVID-19 that likely could have been avoided with vaccination, said Dr. Brian Pollmann, a hospitalist and chief medical officer at HealthPartners' Hutchinson Hospital in central Minnesota.

A healthy woman in her 30s was hospitalized for more than a week, he added. "There was no reason for her to have any severe symptoms from COVID at all but she did. It's been a challenge for staff. … There's just this upwelling of feeling like, 'OK, isn't there anything else we can do for these people?' There's just this level of frustration that all of our nurses have, just seeing these people linger and not do well in their beds all day just struggling to breathe."

COVID-19 hospitalizations in Minnesota increased slightly to 935 on Monday, after declining from a high of 1,008 earlier this month. Greater Minnesota hospitals remained under pressure, caring for just over half of those COVID-19 patients — a trend that hadn't happened in earlier waves — and providing outpatient monoclonal antibody therapies to patients from the Twin Cities who couldn't find closer access.

Health officials remain hopeful that the latest pandemic wave is easing — with the positivity rate of diagnostic testing declining from a recent peak of 8.3% to 7.2%. Such steep declines have signified the end of previous COVID-19 waves in Minnesota, other than brief upticks in infections following the Thanksgiving and Christmas holidays.

Minnesota has tallied 8,581 COVID-19 deaths and 779,749 known coronavirus infections, including 22 deaths and 6,583 infections verified over the weekend and reported by the state Department of Health on Tuesday.

While 86% of COVID-19 deaths have been seniors, Tuesday's additions included two people in their 40s and a Hennepin County resident age 20 to 24. The state has reported 11 total COVID-19 deaths in people younger than 24, including a teenager last week.

With federal approval likely next week of Pfizer COVID-19 vaccine for the 5 to 11 age range, Malcolm said Minnesota is expecting an increased supply of 170,000 more doses to meet the anticipated initial demand.