An infectious disease specialist has suggested Ireland will feel the benefit of coronavirus vaccines when we get three or four million doses of them.
Latest figures show medics across Ireland have now given 930,000 doses of vaccines.
Mass inoculation centres kept working through the Easter weekend in Dublin, Galway and Cork.
While a record of more than 30,000 people received a shot on Good Friday.
Professor Sam McConkey is head of the department of International Health and Tropical Medicine at the Royal College of Surgeons in Ireland.
Newstalk Breakfast host Bobby Kerr asked him when we would start to see the benefits of vaccines to bring infections down.
"I think we've all realised the answer to that depends on when we get the vaccine supply into this country.
"It's very dependent on supply chains.
"Everyone in the world is looking for this - the whole world is a huge demand for this vaccine in every conceivable country.
"That discussion has been very widely had over the last two or three months with some successes but also some failures.
"The answer is it depends on the supply - but certainly once three or four million of us are vaccinated."
Citing Scotland and Israel as examples, he added: "These vaccines really do work to solve the problem in a dramatic way.
"I'll turn around and ask you 'When will we get three or four million of doses of vaccine?' and that's the answer".
On stubbornly high numbers, Prof McConkey said this is down to two factors: the B117, or UK, variant and the implementation of restrictions.
"When one person in a family has that variant, almost everyone else they live with - or a large proportion of the people they live with - catch it.
"Whereas with the previous variants of 2020 often it was only a third or 20% of the family people you live with who caught it.
"So unfortunately this new variant is more infectious and a large proportion of close contacts get it.
"We've seen that in Irish data and around the world.
"The second thing is that maybe our implementation of level five - or what we call level five - today is a different level five from the one we had in May 2020.
"Our level five has changed, it's not quite as strict - I'm not saying that's wrong or right - I'm just saying it's different".
Re-opening from April 12th
On some sectors beginning to re-open next week, he said he is hopeful numbers will stay low.
"Things like outdoor building... they're outdoors, they're building houses with blocks and mortar, carpentry, plumbing and roofing.
"That outdoor, social spaced out activity - the builders are used to wearing hard hats and harnesses and a lot of health and safety gear.
"So it is an industry that's been doing sensible health and safety for decades... so I'm reasonably confident that they'll bring in their health and safety things of gelling your hands, staying away from people and wearing masks".
But he said the issue of sick pay needs to be resolved, so people who may have symptoms are encouraged to stay at home.
"I think employers have got that far now; they've realised that closing down your whole site because of an outbreak of COVID-19 is no good for anyone.
"So you've got to really encourage people with symptoms to stay at home".