The HSE confirmed it is planning its flu vaccine programme, beginning in October, with the potential of running it with a Covid-19 booster shot.
No formal recommendation has yet been made to give people a top-up Covid-19 booster vaccine, although it is looking increasingly likely.
However, the National Immunisation Advisory Committee (NIAC), which will make the decision, has put the HSE on alert to have a plan ready for a possible booster jab roll-out.
Asked how it would operate, the HSE said "flu vaccines and Covid-19 vaccines can be given at the same time".
It could see a person offered a flu jab in one arm and a Covid-19 vaccine in the other.
The HSE has ordered two million doses of flu vaccine for this winter - a quarter of which are for children.
In excess of two million doses of flu vaccine are due to be purchased.
The flu vaccination campaign will begin as it does most years in early October.
"NIAC will indicate the groups for Covid-19 boosters. These cohorts may also be eligible for the flu vaccine," a NIAC spokesperson said.
"Flu vaccines and Covid-19 vaccines can be given at the same time.
"The HSE is currently planning the flu programme with the potential of inclusion of a booster Covid-19 programme,."
The booster jabs would be given to the highest at-risk groups first - nursing home residents, healthcare workers and the over-80s.
The effectiveness of vaccines was underlined yesterday after it emerged that among the 155 adults who have died with Covid-19 since April 1, just seven had been fully vaccinated more than 14 days previously.
In the last fortnight 67pc of cases of the virus in the over-65s were among people who received two vaccines.
This amounts to 764 cases but compares to 3,379 infections when daily cases were this high in February.
It comes as another 1,819 new cases of the virus were diagnosed yesterday.
There were 206 Covid-19 patients in hospital with 36 in intensive care - an increase of three in the previous 24 hours.
Deputy chief medical officer Dr Ronan Glynn last night sought to arrest hesitancy in the remaining section of the population who are unvaccinated.
As of yesterday, 78pc of the adult population and 59.7pc of the entire population was fully vaccinated.
Nearly 90pc have received at least one dose.
"When we see cases in vaccinated people, we need to remember what we are not seeing," Dr Glynn said.
"What we don't see is the very many more infections, hospitalisations and deaths that have been prevented by vaccination.
"Of course, no vaccine is 100pc protective and some people who have been fully vaccinated will still get infected with, and get sick from, Covid-19.
"However, the individual risk of a severe illness or death is much lower than if they had not been vaccinated."
From today vaccine registration will open for children aged 12 to 15 through the HSE vaccine portal.