https://www.cnn.com/2020/12/27/tech/coronavirus-vaccine-passport-apps/index.html
The above CNN Business article discusses development work by several players toward creation of electronic vaccine passports that may (may, not will) help with the restoration of travel. The article acknowledge that a paper equivalent will be needed for folks not equipped with smartphones. I was encouraged by the conclusion of the article [emphasis mine]:
" 'We still don't know if vaccinated people can transmit infection or not,' she [Julie Parsonnet, infectious disease specialist at Stanford University] told CNN Business. 'Until that is clarified, we won't know whether 'passports' will be effective.'
"Still, Behlendorf [executive director of Linux Foundation] anticipates that the rollout and adoption of vaccine passports will happen rather quickly once everything falls into place and expects a variety of apps that can work with each other to be 'widely available' within the first half of 2021.
" 'Rest assured, the nerds are on it,' he said."