The UK could roll out COVID-19 immunity passports — here's how 5 companies pitching for a role say the system could work

· The UK has published proposals for COVID-19 immunity passports and other technologies that could help it track the virus.
· A number of startups have either held talks with government officials or submitted plans of their own, including: Yoti, Onfido, and IDnow.
· Governments around the world are hoping that by tracking...