Influenza activity has increased but remains at low levels, according to the Health Surveillance Protection Centre.
The HSE is urging those eligible to avail of the flu and Covid 19 vaccine, and for parents of eligible babies to avail of the free catch up RSV immunisation over the next four weeks.
Dr. Suzanne Cotter is a Consultant in Public Health Medicine with Public Health HSE Dublin and the North East.
She believes that the flu has arrived three or four weeks early this year.
Speaking on the Joe Finnegan Show this morning, she said she expects an increase week-on-week from now until Christmas.
She explained that a lot of the flu can be prevented by getting vaccinated.
Dr. Cotter said: "The viruses are circulating, it's the flu predominately, it's also RSV.
"The thing is, a lot of the flu can be prevented. Or we can prevent the serious consequences of it, you know, the hospitalisations, going to the ED department, if we get the flu vaccine.
"There is a lot of people who are eligible, and the vaccine is free and easily available in the community," Dr. Cotter added.
