The Health Service Executive has said influenza levels have increased further and are likely to peak in about a week or two.
So far this season there have been 15 deaths and 535 people admitted to hospital due to flu.
Most of the deaths have been in people aged over 65.
There are currently 27 patients in critical care units with flu.
The HSE has said it is still important for people at risk to get the vaccine as the flu season can continue into March or April.
It is also possible that another virus strain may come into play.
The HSE says flu levels may reach levels seen in the 2000/2001 and 2008/2009 seasons but will not reach the pandemic levels of 2009/2010.
Dr Kevin Kelleher, Assistant National Director for Public and Child Health with the HSE, has said there are not enough people being immunised for the flu vaccine to have an impact.
Speaking on RTÉ’s News at One, he said that it was important that at risk groups and medical staff received the vaccine, and when this happened it reduced the risk of flu outbreaks in nursing homes and hospitals.
We're not immunising enough people for it to have a positive impact.
Dr Kelleher continued: "The main way we get the vaccine to work well is by vaccinating the people at risk and then getting the staff, or the carers who are likely to be looking after them, vaccinated as well. So that forms a ring around them, a doughnut around them to prevent them getting the disease. And there's evidence that works well."
