https://br.noticias.yahoo.com/sao-paulo-vai-ao-stf-exigir-passaporte-de-vacina-a-estrangeiros-220348854.html
Im not sure what the purpose of requesting a vaccine passport is in this case since:
A) a phone app does not prevent people from being infected;
B) a phone app does not prevent people from spreading the disease;
C) a phone app does not disclose whether or not the person has the disease (PCR test does that, kind of)
The vaccine passport is used for the most part to prevent people who are unvaccinated to be able to go into enclosed, public settings, so as to be "inconvenienced" just a tad bit in an effort to get the unvaccinated to change their minds. It is obviously not done with the intent to stop the spread of the disease since vaccinated people can be infected as well as spread the disease just as much as the unvaccinated. Everything that is being done Covid-wise revolves around getting people to get vaccinated. And remember, if you wanna follow the Northern Hemisphere model, be ready for multiple vaccines. Dont think that its gonna be the two shots and the booster and you're done.
It's gotten to the point where, ok, if you go along with the agenda you are simply going along with the lie.
In some instances, like this, ignorance rules.