The HSE's online portal for Covid-19 vaccines opens for the mRNA vaccine for 34-year-olds today with 33-year-olds tomorrow, down to 30-year-olds on Sunday.
Under-35s can also opt to get a Johnson and Johnson vaccine in a pharmacy - with 80,000 jabs being distributed to outlets from today.
HSE CEO Paul Reid says the country's five-millionth vaccine will have been administered by the end of today.
