Dr Colm Henry has asked people in the age group to be patient.
HSE Chief Clinical Officer Dr Colm Henry has said there may not be enough Janssen vaccines to meet the demand from the 18-34-year-olds who have applied to receive one.
On Friday, Minister for Health Stephen Donnelly announced that vaccine distribution for the cohort will begin from Monday, 5 July.
From this date, 750 pharmacies throughout the country will begin offering vaccines to the 18-34 age group, beginning with Janssen vaccines and eventually incorporating AstraZeneca vaccines.
Since the announcement, pharmacies around the country were inundated with calls from young people requesting an appointment to receive a Janssen vaccine.
Some pharmacies reported having waiting lists of over 1,000 people, while
Boots Ireland temporarily closed bookings due to the "unprecedented demand".
Appearing on
Saturday with Katie Hannon, Henry was asked how many vaccines each pharmacy can expect to receive in the coming week.
He said there were 50,000 Janssen vaccines "out there in the system" and that another 80,000 will be distributed over the coming week or two.
Henry explained: "We will be distributing those based on.. the relative demand from individual pharmacies and geographical areas.
"It's great to see such interest and engagement... I have no doubt these additional vaccines will be used."
However, he also said: "We may not have enough to meet the demand," before adding: "To underline that point again... this is just one more additional option.
"The other options are... the additional AstraZeneca for which people can enroll in the week beginning 12 July and of course that age-based system which will go down to people in their early 30s and 20s throughout late July and August."
Henry also told the programme that the pace of the vaccine rollout has always been set by the supply.
"What we will be doing is trying to distribute this in the most equitable way we can," Henry said regarding the Janssen vaccines.
"I'd ask people to be patient, to echo the call of my colleagues yesterday."
