As vaccine distribution reaches the 100 million mark in the United States and Americans yearn to return to their normal lives, some state governments and private industries are considering adopting a "vaccine passport" program.

But not Florida.

Gov. Ron DeSantis (R) said Thursday that under no circumstances would Florida impose a state mandate requiring people to show documented proof of their vaccination before traveling or attending large public gatherings like concerts or sporting events, at least not while he is governor.

"I just want to make very clear in Florida, we are not doing any vaccine passports. All those experts said that it was a bad idea. I think it's a bad idea, and so that will not happen. And so folks should get vaccinated, if they want to, we'll obviously provide that, but under no circumstances will the state be asking you to show proof of vaccination, and I don't think private companies should be doing that either," DeSantis said Thursday.

The governor believes it's all Floridians' individual responsibility to decide whether they get the vaccine and what kind of places they go or activities they do.

"To start going down the road of vaccine passports, I mean, you have some of these states saying to go to a sporting event, you have to show either a negative test or a vaccine proof. I think you just got to make decisions. If you want to go to an event, go to an event. If you don't, don't. But to be requiring people to provide all this proof, that's not how you get society back to normal, so we're rejecting any vaccine passports here in the state of Florida," DeSantis said.

The idea of showing proof of vaccination before being permitted to travel places is gaining traction worldwide. On Feb. 21, Israel introduced the "green pass," an app Israelis can download to display proof that someone has recovered from COVID-19. Advertising for the green pass promoted the idea that anyone with the pass could return to life as normal, going where they please without social distancing or masks.

Currently, the Biden administration requires international travelers who want to fly to the United States to provide proof of a negative COVID-19 test before they can travel. The international airline industry is considering taking the next step by requiring travelers to present a digital certificate showing proof of vaccination.

In the European Union, a proposal to create a Digital Green Certificate to facilitate travel across its 27 member countries will be discussed at the next summit of EU leaders. The certificate would "serve as proof that a person has either been vaccinated against COVID-19, received a negative test result or recovered from COVID-19," according to NPR.

Several health experts have criticized the idea, warning that free Americans who decline to receive a vaccine could be relegated to second-class status.

"The vaccine hesitancy data show that the people who are hesitant to take vaccines actually tend to be the working class people, poor, poor people, minority populations. We're going to then turn around and say, 'You have to have a vaccine passport to participate in American life,' it's going to be a new vaccine Jim Crow. It's a huge, huge mistake that will undermine trust in public health, and I think it's just morally, it's just morally wrong," Dr. Jay Bhattacharya of Stanford University said, speaking at a roundtable discussion with DeSantis and other health experts Thursday.

The federal government has explored the idea of some kind of vaccination passport. President Biden signed an executive order in January directing government agencies to "assess the feasibility" of linking coronavirus vaccine certificates with other vaccination records and providing digital copies for international travelers to use.

The White House has since rejected the idea of a federal mandate for domestic vaccination passports, which would require a database of who has been vaccinated and who has not.

"It's not the role of the government to hold that data and to do that," White House senior adviser for COVID-19 response Andy Slavitt said during a briefing Monday.

He added that whatever system Americans eventually adopt to demonstrate they've been vaccinated "should be private. The data should be secure. Access to it should be free. It should be available both digitally and in paper and in multiple languages. And it should be open source."