More than 19 percent of Americans are fully vaccinated against the coronavirus and upward of 665 million vaccine doses have been administered worldwide. As these numbers continue to rise, countries have begun issuing or considering “vaccine passports.” Vaccine passports — proof through a phone app or on a piece of paper that you’ve had your shots — are a potential ticket to freedom for millions of vaccinated people around the world. Israel already has them. The European Union and China have also announced a version of them. In the United States, there’s talk about what such a certification might look like. But vaccine passports also raise huge ethical questions, with 85 percent of shots worldwide having been administered in wealthier countries. And with private tech companies working on creating these passports in the United States, there’s worry about the risks of sharing health records with third-party apps. Both Texas and Florida have prohibited government-mandated vaccine passports. On today’s episode, our guests debate the concept of a vaccine passport and discuss the ethical and privacy considerations that come along with them. Natalie Kofler is a molecular biologist and bioethicist at Harvard Medical School. Ramin Bastani is the founder and chief executive of Healthvana, a patient platform that delivers test results and is supplying vaccine passports. He says we should think of them more like an everyday health record. Then, we turn to listener voice mail messages as they share their thoughts on the reopening of schools. Referenced in this episode: “Vaccine Passports Won’t Get us Out of the Pandemic,” in The Times. “Vaccinated Workers Are Getting Benefits That Those Without Covid Shots Won’t,” in Bloomberg, about vaccine passports in Israel. WBUR’s episode on the pros and cons of vaccine passports. Share your arguments with us: We want to hear what you’re arguing about with your family, your friends and your frenemies. Leave us a voice mail message at (347) 915-4324. We may use excerpts from your audio in a future episode. You can find transcripts (posted midday) and more episodes of "The Argument" at nytimes.com/the-argument, and you can find Jane on Twitter @janecoaston. “The Argument” is produced by Phoebe Lett, Elisa Gutierrez and Vishakha Darbha and edited by Alison Bruzek and Paula Szuchman; fact-checking by Kate Sinclair; music and sound design by Isaac Jones.