Influenza activity is likely to have peaked in December but remained high in the last week, according to the Health Service Executive.
Figures up to 12 January show that so far this season, there have been 2,707 hospital admissions due to flu.
The number of influenza related deaths recorded is 44. Most of the deaths were in older people.
Confirmed influenza hospitalisations are at high levels.
Influenza A is the main circulating virus.
Separately, the HSE said that emergency department attendances and admissions reduced this week, compared to last week.