As of today, proof of vaccine, recovery, or negative test is no longer required.
FFP 2 masks are still mandatory on public transport (including at train stations and airports), when using taxis and in essentials shops (e. g. supermarkets, post offices and pharmacies).
Here is the link to the official Gov. website:
https://www.austria.info/en/service-and-facts/coronavirus-information?location=uk