Children are expected to be at risk of a fresh barrage of flu that could hit Ireland in a month's time.
Although the current winter outbreak, which has so far caused 28 deaths, has peaked and is set to slowly recede in the coming weeks, there is a threat of a second upsurge in early February, public health officials warned.
Dr Kevin Kelleher, of the HSE, said that while the A (H3N2) strain had been dominant here for weeks, the United States had been mainly hit by influenza B.
There is a risk that this B strain could strike here in weeks.
And it could become the dominant virus circulating.
"Influenza B is the flu predominating in North America," he said.
The second ramping up of the flu could come when the country could be in the middle of a general election campaign, and might fuel another trolley crisis.
Influenza B tends to be a more stable type of flu, not undergoing too much mutation from prior years, and as a result, a large number of adults are immune from previous exposure.
This means it is children and teens who are most prone to the illness.
They in turn can pass it on to vulnerable adults such as grandparents.
Dr Kelleher said it was perturbing that so many outbreaks of flu this winter had happened in healthcare settings such as hospitals and residential homes.
An outbreak is where flu is passed on from one person to another.
Dr Kelleher said that there had been 90 outbreak reports already.
This is more than for the whole season last year.
Of these, 79 were in healthcare settings.
"We should not be getting outbreaks in healthcare settings if we got our vaccination right."
Staff vaccination rates can still range from 30-50pc.
The majority of the deaths have occurred in people aged 65 years and older.
Two of the deaths were among children under 15 years of age.
So far this winter, 2,038 patients have been hospitalised with flu.
There have been 72 patients admitted to critical-care units, the majority due to flu.
Six in 10 of those admitted to intensive care have been over the age of 65 years.
Dublin, Cork, Kerry and Clare have been worst affected by the flu while fewer cases were seen in the midlands and north-west.