Registration will begin with those aged 39 on Sunday.
Registration for the Covid-19 vaccine begins on Sunday for people aged 35 to 39, starting with 39-year-olds.
The HSE has said people in the 20-29 age cohort can expect to receive a first dose of a Covid-19 vaccine by late August into early September.
Similarly to when the portal was opened for previous age groups, those aged 39 will be able to register on Sunday first.
This is before 38-year-olds can apply on Monday, with registration working backwards throughout the ages in the subsequent days.
HSE Chief Clinical Officer Dr Colm Henry made the comments on the
Brendan O'Connor show on Saturday, where he gave details regarding the timeline for the future administration of vaccine doses in Ireland.
He said he expects that the first doses for 40-49s will be complete in the next couple of weeks, with this cohort receiving their second dose one month later at around the start of August "all things going well".
Meanwhile, 30-39s can expect their first dose in the first weeks of August, with a second one month later.
Asked if this meant 20-29s would be looking at getting their first doses in late August into September, Henry responded: "Correct, all supply dependent."
To register online for a vaccine, you will need a mobile phone number, an email address, your PPS number and your Eircode.
If you do not have these things, you are advised to call the Covid-19 helpline to register by phone instead.
For more information on how to register for a Covid-19 vaccine in Ireland using the new portal, check out JOE's handy guide
here.
