There have been 44 deaths from flu so far this season, according to the HSE.
Last week 609 people were admitted with flu, bringing the season total to 2,707. Most of those who died were aged 65 years and older.
There were 94 people admitted to intensive care and 60% are aged over 65.
HSE assistant national director of public health and child health, Dr Kevin Kelleher, said it appears that the “worst is over”.
However, while there was "clear evidence" that the flu season had peaked last month, he said, it could start to increase again.
“While most of Europe is experiencing the same sort of flu viruses as we are. In North America, their flu is very different. When that happened in the past it has on occasion caused a blip in our flu season and it always seems to come at the end,” he said at the HSE's weekly winter plan update.
“But on the whole, the evidence would suggest that we are in the second half of the flu season,” he added.
Dr Kelleher expected that the number of deaths from would reach between 100 and 120 this year.
The level of flu was as high as it was two years ago, when the country experienced a bad flu season, he pointed out.
Children aged under four years and those aged five to 14 were most affected by the flu this season but the numbers in these groups has now dropped.
“So the flu before Christmas was very much a feature of children,” he said.
Dr Kelleher said there were 107 respiratory disease outbreaks reported and 82 were confirmed as flu. 97 of the outbreaks were in healthcare settings.
The HSE is getting better at identifying outbreaks, he said, but it is concerning that so many are happening in healthcare settings.
The HSE's national director of national services, Joe Ryan, said hospital emergency department attendances and admissions fell by around 5% last week, compared to the previous week and were “early signs” of abatement in flu levels.
Meanwhile, hospital consultants say they have put forward "practical workable" solutions to address waiting lists and the trolley crisis during talks with Health Minister, Simon Harris.
President of the Irish Hospital Consultants Association, Dr Donal O'Hanlon, said they appealed to the minister to put politics aside and patients first by committing to effective targets to deliver timely care which at least match Britain's National Health Service.