Walk-in COVID-19 vaccine centres will offer second dose vaccines from today.
So far, the walk-in centres had been limited to just first doses.
However, this weekend will see a number of dedicated second dose walk-in clinics opening across the country.
They'll be open for people who received their first dose of a Pfizer vaccine at least 21 days ago, or anyone who received their first Moderna jab at least 28 days ago.
People are being asked to check the HSE's walk-in clinic list before attending, as the second dose clinics are operating only at specific times.
There are a smaller number of Moderna vaccination clinics, with most sites only offering second dose Pfizer vaccines.
People will only be able to receive a second dose of the vaccine they've already received - so anyone who received a Moderna vaccine must attend a designated Moderna vaccine walk-in clinic.
Today's dose two clinics include Páirc Uí Chaoimh in Cork, Galway Racecourse and Midlands Park Hotel in Laois.
HSE CEO Paul Reid yesterday said walk-in clinics will continue this weekend and into next week.
He said health officials are now prioritising walk-in clinics in areas "where we're seeing high case levels of the virus".
Around 84% of the adult population has now been at least partially vaccinated, with over 90% fully vaccinated.
Over 540,000 mRNA vaccines arrived in Ireland this week, bolstered by the first tranche of extra vaccines from Romania.
A similar number of vaccines is expected to arrive again next week.