People aged in their 20s are not expected to be given an opportunity to have access to a Covid-19 vaccine until late August or early September.
HSE Chief Clinical Officer (CCO) Dr. Colm Henry said the HSE expects those aged over 40-years-old who have registered for a vaccine will receive one over the next two weeks.
From tomorrow, those aged between 35-39 will be able to register online for their Covid-19 vaccine.
Henry said the HSE is expecting a strong uptake in this age cohort.
He said the majority of people in this age cohort will receive their first vaccine dose by the end of July.
Once the over-50s have received their second vaccine, the vaccine supply will be limited to Pfizer and Moderna, as these are the only ones which can currently be used on those under-50 in Ireland.
Henry went on to say that if supplies continue as expected, those aged in their 20s will receive their first vaccine by late August or early September.