Gov. Tim Walz on Thursday touted the state's new immunization app as a convenient option for people to keep track of vaccination records and pushed back on political critics for "false" comments likening it to a vaccine passport system.

"Scaring people and calling it a vaccine passport is wrong," Walz said Thursday. "This needs to end: One in 500 Americans have died of COVID. It is the number one killer in America, above cancer, above heart disease."

State health officials said the Docket app, unveiled Wednesday, was rolled out in response to a flood of requests from Minnesotans who want easy access to their — and their children's — vaccination histories, as more schools and private employers require proof that they've received the shot.

But on Thursday, Senate Health and Human Services Committee Chairwoman Michelle Benson, R-Ham Lake, called the move a "significant overreach of government" that will provide third-party access to personal health data.

"The Docket app essentially serves as a government-approved vaccine passport, despite Walz's declaration he had 'no intention' of implementing one," said Benson, who is also a Republican candidate for governor. "In fact, the Senate voted with bipartisan support to stop vaccine passports in Minnesota. Citizens already have access to digital vaccination records if they desired."

Walz said the app is voluntary and Benson was trying to scare people by likening it to a vaccine passport, a system used to prove that people have either tested negative or been vaccinated against COVID.

"What I need the senator to do is to try to get people in her district, which has one of the lowest vaccination rates, to try and get that number [up]," he said. "It's absolutely nonsense. You can use the app if you want to."

There's growing pushback among conservatives against vaccine mandates and masking requirements, an issue that drew about 2,000 people to a rally at the Capitol in August. At that event, legislative Republicans signaled concerns over Minnesota Department of Health Commissioner Jan Malcolm's response to the pandemic and said the state was developing an app behind the scenes.

Those concerns, they said, have prompted Republicans in control of the Senate to take another look at her appointment to Walz's administration. Benson said the app should have been brought to legislators before it was rolled out to the public.

Lawmakers had planned to gather in September for a special session to send out $250 million in checks to workers on the front line of the pandemic, but the legislative working group in charge of crafting a deal missed a deadline and is still negotiating the details.

Walz also said he hasn't secured a guarantee from Republicans that they won't fire Malcolm from her job if he calls them back to St. Paul. Republicans in the Senate rejected two of Walz's commissioners last year and prompted another commissioner to resign in July rather than face likely rejection.

With hospital beds filling up and cases rising in classrooms, Walz said he would not call lawmakers back without agreement on Malcolm's appointment.

"There are things that are just plain wrong," he said. "Why in God's name would that be the order of business right now? I want to get this other work done, but I'm not going to lose the top health official in the state of Minnesota."