18 to 34-year-olds will be able to get vaccinated in pharmacies from Monday.
The official advice from NIAC is under 50's should get an mRNA vaccine such as Pfizer where possible.
However, 18 to 34-year-olds who want an earlier vaccination will be able to get the one-shot Johnson and Johnson jab in a local pharmacy.
Anyone in that age group can contact a participating pharmacy to book their appointment.
The HSE says 53,000 Johnson and Johnson vaccines are available at pharmacies nationally.
It says there are an additional 70,000 doses available at short notice "if needed".