If you are from the UK the info is on their site, same should be true for other Countries.
MSC REMOVE COVID - BREAKING NEWS
Mediterranean, Norway, Red Sea, Dubai and Southern Caribbean (Barbados) - Starting from 12 February (departure date) for all guests of any age it will be no longer required to be fully vaccinated against covid-19 or to bring pre-boarding test.
IMPORTANT NOTE: All guests arriving or in transit from China or Hong Kong, are requested to submit a negative test result (Antigen/PCR) performed within 48 hours before departure, in compliance with the regulation of landing country