The Health Minister is warning of an "extremely busy" January for the health service.
Simon Harris says it is important emergency departments are able to cope with the demand.
He is encouraging people to get treatment in the appropriate place.
HSE National Clinical Advisor Dr Vida Hamilton says it is important people get vaccinated over winter.
"Well there are loads of viruses about at wintertime and 20% of people who have to be admitted to hospital during the winter is because of chest infections," said Dr Hamilton.
"So the best way to stay well this winter and avoid having to be admitted to hospital is to get your vaccination."