What is a COVID vaccine passport and how would it work?

A "vaccine passport" is documentation affirming that a person has received the COVID-19 vaccine.

Those in favor of mandating vaccine certifications argue that the documentation could facilitate business reopenings, mass events and international travel. Although U.S. public schools in all 50 states have required students to receive their vaccines unless schools approve certain medical or religious exemptions, those against a COVID-19-specific vaccine passport say requiring documentation proving immunization in exchange for goods or services raise privacy questions. Republicans have largely condemned the idea of requiring documentation that proves a person has been inoculated in order for that person to participate in certain public activities -- an idea that some states and countries have floated or enacted.