Please see
https://www.austria.info/en/service-and-facts/coronavirus-information/entry-regulations
and
https://www.austria.info/en/service-and-facts/coronavirus-information
Also the hotel rules in English and in German
https://kitz.hotel-kaiserhof.at/en/riskfree-holidays
https://kitz.hotel-kaiserhof.at/de/risikofreier-urlaub
We expect all participants to be fully vaccinated against corona virus.