A leading figure in the HSE says medical staff not getting the flu vaccine is leading to outbreaks in hospitals.
28 people have died as a result of the flu so far this season, up from 22 on this day last week.
It comes as hospitals have this week seen the highest numbers waiting on trolleys since records began.
Around half of hospital staff got the flu vaccine this season.
The HSE's Dr Kevin Kelleher - Assistant National Director of Health Protection - says the take up needs to be higher.
"I mean, if nobody was being vaccinated in hospitals, flu would fly around hospitals massively." said Dr Kelleher.
"By the very nature of getting staff vaccinated, that reduces the chance for flu to get transmitted around the hospital.
"The more we get people to be vaccinated, the better it will be within our system."
Earlier today, chief executive of the HSE Paul Reid has said he would like to see fewer emergency departments around Ireland.
It would be a policy decision for Government, he told Newstalk Breakfast, but he believes numbers need to be “really assessed.”
Mr Reid said there is a need to strengthen community care to provide some relief to hospitals.
“If we keep doing everything the same as we've been doing it, we'll continue to have the same answer and have an overcrowding issue.”