The World Health Organization has just released a guiding document for a digital vaccine certificate that will be blockchain based. This will be used to implement a vaccine passport in every country. It’s funded by the Bill & Melinda Gate’s Foundation & Rockefeller Foundation.

“A digital vaccination certificate that documents a person’s current vaccination status to protect against COVID-19 can then be used for continuity of care or as proof of vaccination for purposes other than health care. The approach could eventually be extended to capture vaccination status to protect against other diseases.”

https://www.who.int/publications/i/item/WHO-2019-nCoV-Digital_certificates-vaccination-2021.1