▶ Watch Video: Legal, medical issues raised with vaccine passports For the first time in nearly two years, some sections of Yankee Stadium on Friday were basically filled only with fans who are fully vaccinated against COVID-19. “At first you’re a little bit nervous, and then you’re like we’re all vaccinated, everyone around us is vaccinated,” one fan told CBS News’ Brook Silva-Braga. They could prove that they were vaccinated with their paper vaccine card or New York’s Excelsior Pass—an app that pulls from existing state records. But, for now, just a handful of New York sports venues are using the app. “You just download the app, and they ask you a few questions, they give you the pass, and now I don’t have to carry my card around,” said one fan as he pulled up the app. But as gyms, theaters, and airplanes also start making new rules, it’s still unclear exactly how they’ll verify vaccinations or how much of our privacy will be sacrificed in return. Dr. Tom Frieden, the former director of the CDC under President Obama, supports the so-called “vaccine passports,” but under certain conditions. “It should be voluntary. If you don’t want it, you don’t have to have it. It should be accurate, so can’t be falsified easily. And it should be secure, so the data is private and not used unless you want it to be used,” Frieden said. It may sound simple, but it is a hard sell for the millions who distrust government mandates and big tech intrusions. “It’s gotten so controversial that the federal government is not pursuing a standard vaccine certificate,” Frieden said. Governors and lawmakers in 10 Republican-led states have already banned or limited vaccine passports, including Florida. “We’re not doing any vaccine passports. That’s totally unacceptable,” Florida governor Ron DeSantis said earlier this month during a press conference of the signing of SB 2006. The bill bans businesses from requiring customers to show proof they have been vaccinated against COVID-19 in order to get service. The bill was signed just days before the South Beach Wine and Food Festival, America’s largest food festival, which is now underway. Lee Brian Schrager, the festival’s founder and director, said he spent months working with city and state officials to plan and create a safe, comfortable experience to bring the festival back for its 20th anniversary. In March, the festival announced that it would require attendees to be vaccinated or show proof of a negative COVID-19 test. But DeSantis’ order negated Schrager’s original plan. “I wanted to ensure that anyone attending our festival, whether they were our talent coming in or our sponsors or consumers locally, that we did everything that we felt was the right thing to do. And it was my decision. I wanted to require proof of vaccination and or proof of a negative COVID test, and in the end we had to abide by with what the governor would allow us to do,” Schrager told CBS News. The festival adjusted to the new rules by adding a SIM check program, where attendees are required to attest to vaccination or negative COVID test, and added COVID-sniffing dogs to entrances of events. Along with big events, the cruise industry has also been impacted by DeSantis’ order. Norwegian Cruise Line could bypass Florida ports because of the state’s new ban. While on the other side of the political divide, Governor Andrew Cuomo’s plan to safely resume normal activities, from concerts to cruise ships to sporting events, relies in part on the use of vaccine passports. At Radio City Music Hall, Governor Andrew Cuomo on Monday made it clear if New Yorkers want to attend concerts and shows at the music hall, they must be vaccinated. “You can go 100% vaccinated. We want to encourage people to get vaccinated,” he said. But vetting COVID-19 vaccination cards using software like the Excelsior Pass raises red flags for privacy advocate Albert Fox Cahn. He said the pass is not secure and is “invasive.” “We don’t actually understand how the software was designed,” Cahn said. Some supporters of digital records say those paper cards are too easy to forge. But Cahn argues Excelsior pass is no better. He said he was able to download a stranger’s pass in just minutes. New York officials say a photo ID requirement solves that problem. But for the less tech-savvy, just using the app could be a struggle. “I think we’re going to exclude millions of Americans without photo ID, without access to smartphones,” Cahn said. But is it even legal for businesses to require the vaccine? Harvard’s Carmel Schachar, who studies medical law, said it almost certainly is legal, but there are religious and medical exceptions and a looming split based on where you work “So you may have employers say, ‘For our employees who report to the New York office, you have to be vaccinated, and for our employees who report to the Denver office, we’re not going to ask any questions,'” she said. As the country cautiously returns to a pre-COVID time, Frieden says that the strongest verification of safety may be the security provided by the vaccines themselves. “If you’ve been vaccinated, it’s really great at protecting you from getting seriously ill, and it’s really great at preventing you from spreading it to others,” he said.