Vaccine passports: The promise and pitfalls

Millions of people are being vaccinated against the coronavirus every day. While that’s undoubtedly good news, this growing share of the population with COVID-19 immunity creates a conundrum for decision makers as they plan a gradual reopening of the country. On one hand, there are costs to asking vaccinated people to endure the isolation of lockdowns when they face little risk from the virus. On the other, lifting restrictions to accommodate them would put unvaccinated people in danger.

Several countries have begun exploring a possible solution to this problem: vaccine...