The Covid-19 vaccine portal has opened for 49 year olds to register.
High risk patients and frontline healthcare workers who have yet to receive an appointment can also register.
People can sign up by phone or online, and will be given Pfizer or Moderna when vaccinations start later this month.
However it's expected Johnson and Johnson and AstraZeneca will be offered if they aren't available at the time.
Consultant in Infectious Diseases at St James' Hospital in Dublin, Professor Cliona Ni Cheallaigh, says the choice will help speed up the vaccine programme: