Countries worldwide have announced plans to implement vaccine passports—electronic or paper credentials that show a person has immunity to Covid-19 through either vaccination or recovery from the disease. U.S. states and private businesses seem ready to follow suit. New York State has launched the Excelsior Pass for New Yorkers to prove immunity with a machine-readable QR (“quick response”) code. Walmart will provide an app letting customers vaccinated at the store share their status. At least 17 private initiatives to provide vaccine credentials are in development.
