The HSE is urging people in at risk groups to get vaccinated ahead of the winter.
On average between 200 and 500 people die each year from flu related illness.
The HSE says the elderly, people with chronic illness and those with a weakened immune systems should get vaccinated.
Flu is spread by coughing and sneezing so people should cover their nose and mouth with a tissue, disposing of the tissue as soon as possible and washing their hands with soap and water as soon as possible to help prevent the spread of flu.
Anyone who gets flu should stay at home, rest, drink plenty of fluids and use over-the-counter flu remedies to ease symptoms. People in high-risk categories should contact their GP if they develop flu symptoms.
Dr Brenda Corcoran is Head of the HSE's National Immunisation Office:
