We translated the most common tourist activities from the government’s super green pass chart into English so you can see which require a super green pass.

To check the current entry requirements for your specific country of origin and any countries you have traveled to in the 14 days prior to entry to Italy, use the Italian foreign ministry’s interactive survey.

No. Eligible equivalent foreign vaccination certificates in Italy follow the same standards as those imposed by the Italian health ministry for green pass purposes. In Italy, a vaccination certificate is valid starting on the 15th day after the first dose through until the second dose, and then validity continues immediately starting from the date of the second dose and remains valid as of the date of any subsequent dose.

Our source for this answer is the Italian government's green pass website (in Italian only) FAQ page. The only timeframe this page states for the 2nd and subsequent booster doses is that it can take up to 48 hours to generate the updated certificate (for the Italian version of the EU Digital Covid Certificate). But in terms of validity, the only time it mentions there is a wait time is after the first dose (14-day wait).