A SURGE in flu cases led to renewed calls today for people to get vaccinated.
The number of people falling ill with flu has doubled in the past week.
The Health Protection Surveillance Centre warned today older people and people with health problems should get the flu jab as soon as possible.
Dr Joan O'Donnell, a specialist in public health medicine, said it is "not too late" to get vaccinated.
The seasonal flu virus has become active and the current cycle will last for six to eight weeks. It can take two weeks for a vaccination to offer full protection so it is worthwhile for vulnerable people to get the jab.
Ireland has escaped lightly this winter compared with recent years' flu levels.
However, rates of flu-like illness have risen from 15.7 per 100,000 to 26.2 per 100,000 this month and are now above "threshold levels".
This means that flu is "actively circulating" the community.
"People who are at risk of the complications of flu need to get vaccinated now. The vaccine is available free of charge from GPs for all people in at-risk groups, and from pharmacists for everyone aged 65 and over," said Dr O'Donnell.
"An administration charge may apply to people who don't hold medical cards or GP visit cards," she added.
The most recent surveillance report showed three people have died from flu this winter.
Although this is the official number, many more will have died due to complications.
Dr O'Donnell said the seasonal flu vaccine is a safe vaccine. It is a separate vaccine from the swine flu vaccine, which resulted in complications for a small percentage of people.
People with chronic bronchitis, diabetes, heart conditions, and weakened immune systems should ensure they get the flu vaccine. Influenza can lead to complications such as pneumonia and even death.