NPHET has approved the easing of almost all COVID-19 restrictions, with Cabinet ministers meeting later to agree a timeline.
It is expected the hospitality sector - including nightclubs - will return to normal opening hours over the coming days.
Relief and jubilation among Cabinet ministers on Thursday night as the NPHET letter arrived, with one saying it felt like a weight lifted off the shoulders.
Public health officials have recommended a sweeping lifting of COVID restrictions.
That includes ending early closing times for hospitality, including nightclubs, removing capacity limits at live events and matches; and scrapping the need to have a COVID-19 pass to enter a bar or restaurant.
The only measures likely to remain are mask wearing in shops and on public transport, COVID Certificates for travel, some special guidance for schools - and the test, trace and isolate system.
Health officials also greenlit a phased return to the office for workers.
NPHET has not set out a timeline for Government, leaving that for politicians to decide later.
Ministers say they have no intention of hanging about, but some legal regulations do need to be unwound.
Sources left open the idea that normal trading hours for hospitality could return from Saturday, with nightclubs also opening.
If not Saturday, Monday was the other date being discussed.
However there is a belief it will be impossible to police a curfew this weekend, now the contents of the NPHET letter are public knowledge.
The Government party leaders will meet this morning and the full Cabinet will discuss things in the afternoon.
Taoiseach Micheál Martin plans to address the nation at 6.00pm.