Water is entirely safe to drink and standards of hygiene in restaurants, cafes and public houses are exceptionally high, minimising the chances of bacteria-related illnesses. There are no specific vaccinations required to visit the Republic of Ireland although those arriving from countries where yellow fever is present, will be required to show certification of vaccination.
Standards of medical care in both public and private hospitals is high and if you are unfortunate enough to be taken ill during your trip, you can rest assured that you will be in good hands should you require medical treatment.