The head of the HSE says it is ready to adjust the vaccination programme if the government decides to prioritise younger people.
The Health Minister has asked officials to look at the possibility of vaccinating under 30s ahead of older groups in a bid to reduce transmission rates.
It would see those aged 18 to 30 get the jab before people in their 30s, 40s and 50s.
Labour Party leader, Alan Kelly, said the Minister's request for a review of the vaccine programme has undermined the government's own argument the priority list be based on age Mr Kelly said there must be "serious questions" about Mr Donnelly's management of the vaccine rollout.
"If the Taoiseach hasn't already spoken to him today, he needs to very quickly because this has caused utter confusion and has undermined the Government and its own arguments in relation to the vaccine rollout in the first place," said Mr Kelly.
HSE chief executive Paul Reid says its plan will only change if directed to do so.
He said they are not aware of any plans to change the vaccine priority list at the moment.
"We are working off medical, scientific advice from the National Immunisation Advice Committee which is very strong and compelling to administer the vaccines based on age," said Mr Reid.
"That is where the highest risk is and that is the plan agreed by Government and that is the plan we are working through right now.
"If at any stage there are changed by the Government, we will change the plan accordingly but all of the medical and scientific advice is strongly to administer based on age."
Mr Reid said today that almost 1.2 million doses of Covid vaccine have been administered with 22% of the eligible population having received a first dose.
The latest data shows over 34,500 doses administered on Thursday.
"The real measures of sickness, hospitalisations, ICU and mortality all radically reduced," said Mr Reid.
The number of people with Covid-19 in hospital is at its lowest point in more than six months.
This morning, 183 patients with the virus are being treated including 50 in intensive care units.
There have been no new admissions to ICU in the last 24 hours.