For the warmer destinations it is sometimes necessary to be vaccinated. This can be for simple things like diphtheria, tetanus and polio but also sometimes against rabies or a prophylaxis against malaria. There are various online options to determine whether or not you need a vaccination.
Personally I always contact my general practitioner who can determine exactly what I do and do not need for my next fishing trip. Some vaccinations consist of more than one dose, so it is necessary to arrange this on time and not to wait too long.
For the regular health during the fishing trip it is always wise to bring basic medication and medical supplies. Things like sun lotion, plasters, paracetamol, scissors, disinfectant, nasal spray, ORS, diarrhoea inhibitors and more of these basic things are always wise to bring with you on a fishing trip. But also a simple fishing cap, sunglasses and a long-sleeved shirt against the sun are important measures for your own health during the fishing trip.