Don't leave these till the last minute. Wherever you're travelling we recommend you have a minimum of Influenza (seasonal), Hepatitis A and Tetanus/Diphtheria vaccinations.
We also strongly advise you to seek advice from either your doctor or an approved public health travel advisory service to identify any specific vaccinations or health precautions required for each port of call. E.g.
Some countries strictly enforce certain health requirements. If you don't have correct vaccinations, you may not be able to go ashore at certain destinations. Additionally, some local authorities may impose a monetary fine or deny the ship entry into the port.