BRASILIA—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. The government put off for a week implementing new health requirements for travelers arriving in Brazil due to the attack. “The health ministry reports that in the early hours of Friday it suffered an incident that temporarily compromised some of its systems … which are currently unavailable,” it said in a statement. Police said they were investigating the attack. The alleged hackers, calling themselves Lapsus$ Group posted a message on the website saying that internal data had been copied and deleted. “Contact us if you want the data back,” it said, in an apparent ransomware attack. The message, which included e-mail and Telegram contact info, had been removed by Friday afternoon, but the web …