That did not take long: 2 weeks from “rules out vaccine passports” to “let’s consider them”

Feb 7: Covid: Minister rules out vaccine passports in UK – BBC News

Feb 23: UK Mulls Vaccine Passport Options to Help Businesses Reopen

“U.K. firms may be allowed to demand proof that customers do not have coronavirus under options being considered to help businesses reopen after the pandemic.”

UK is considering allowing a substitution of a Covid-19 test result for a vaccine passport. In the UK, such tests are free – albeit, the tests when used for asymptomatic screening have a false positive problem that puts you at risk of quarantine each time you get tested. In the U.S. tests can cost up to $125 each (worst case when done at an airport).