Which effectively takes vaccine passports offline:

Brazil’s health ministry said its website was hit on Friday by a hacker attack that took several systems down, including one with information about the national immunization program and another used to issue digital vaccination certificates.

Source: Brazil health ministry website hit by hackers, vaccination data targeted | Reuters

There is an unconfirmed report that the hackers deleted all vaccination records. Presumably there are backups, but who knows?

By EdwardM