Vaccination of people over 50 is set to get underway in the next two to three weeks, HSE CEO Paul Reid has said.
He said people in younger age groups should also soon have a timeline for when they'll be able to register, once officials have signed off on the latest revisions to their vaccine plan.
While announcing an easing of restrictions for May and June yesterday evening, Taoiseach Micheál Martin confirmed 50-59 year-olds will be able to register for a vaccine from next week.
Mr Reid told Newstalk Breakfast registration will work in the same way as it did for over 60s - starting with 59-year-olds, and then working down through the different ages.
He said: “We’re making good progress in getting through the 60-69s - there are now over 305,000 people registered on the portal.
“We made a recommendation to continue on now and open [registration] to 50-59s. They will commence over the next two to three weeks.”
He said people can expect to hear about an appointment around two weeks after they register.
Authorities are finalising their latest plan at the moment, and it's currently unclear which vaccines over 50s will be receiving.
The Johnson & Johnson jab is currently only recommended for over 50s, but supplies of the one-dose vaccine remain limited.
Mr Reid said supply is expected to pick up in May and June, and authorities are now working with all suppliers to get more certainty on deliveries for the coming months.
He said the current pace of vaccination will continue and they're 'striving' to hit the target of 82% of adults having at least one dose by the end of June.
The HSE CEO said they expect to administer 220,000 - 240,000 doses next week.
30 mass vaccination centres are open now, with six more opening next week and the final two the following week.
In terms of the reopening plans, Mr Reid said the HSE shares the "cautious optimism" expressed by Government yesterday.
He said there is a need for caution as large amounts of the population still aren't vaccinated.
However, he said there have been big benefits for those groups who already have received their vaccine.
He also noted the lengthy lockdowns and restrictions have an impact on the wider healthcare system - including delayed care the HSE now needs to get back to.