Director of the National Virus Reference Laboratory Cillian de Gascun has said there is an expectation that at some point during this coming week the coronavirus cases will plateau.
Speaking on RTÉ's Saturday with Katie Hannon, he also said the number of close contacts is decreasing with people realising how "precarious" the situation is at the moment.
However, he warned that there is "most certainly" more cases of the virus in the community than the daily figures as contacts of confirmed cases are not being tested.
He said the measures in Level 5 restrictions that are implemented will work but people need to be more vigilant with new strains of the virus being more transmissible.
"The UK variant is of more concern to us purely because of the amount of virus on the island because we know it is transmitting in the community."
With the variant detected in South Africa he said they know where the three cases are and they have been contained and controlled and he understands there was no onward transmission.
He said they need more data to check how effective the Covid-19 vaccine is against the variant first identified in South Africa.
Meanwhile, a leading consultant in infectious disease has said that the current trend of thousands of new cases of Covid-19 per day will translate into more and more people ending up in hospital in the next week to 10 days.
Paddy Mallon, a professor in microbial diseases at UCD and a consultant at St Vincent's University Hospital in Dublin, said this is a "very bleak outlook for our health services at the moment".
Professor Mallon said he is seeing a big increase in the number of people presenting to the Emergency Department with Covid and being admitted within the hospital and that a surge plan has been enacted.
He warned that while extra capacity is available, space in the health system is not endless.
"Most of the ICU's in the country work near full capacity day to day. The fact that we have additional large numbers presenting means they will be exceeding normal day to day bed space and capacity. There is a surge capacity. There are ventilators available. There is space but it is not endless," he explained.
Prof Mallon said the virus needs to be controlled in the community, otherwise "we will see some very unfortunate events".
"We don't need to flatten the curve, we need to crush the curve. We need to get numbers in the community down into the hundreds and preferably into double figures. We cannot continue to operate with thousands of cases per day".
He said that this might take a few weeks to achieve but it can happen if everyone stays away from each other and stays at home.
While GPs reported being exceptionally busy referring patients to be tested over the Christmas and New Years period, this appears to have slowed down slightly.
However, one doctor in Drogheda said this activity has been replaced by referring on patients with Covid-19 to hospital for further assessment.
Dr Amy Morgan said: "You can now see how the infections that have taken place over the Christmas and New Year period are now actually starting to deteriorate clinically in the community and that's hugely concerning."
Dr Morgan said they are still referring a lot of people for testing, but some patients who have already tested positive are now deteriorating.
She said what GPs are seeing matches up with the "lag time" that is often talked about between when a person first becomes infected, shows symptoms, and becomes ill enough to be hospitalised.
Prof Mallon said that he does not believe the disease has changed dramatically between the first wave last March and now.
Professor of Experimental Immunology at Trinity College Dublin Kingston Mills said he believes those who have been infected with Covid-19 and recovered do "not need to be vaccinated" as the chances of reinfection are low and it would mean saving vaccine doses for others.
Speaking on RTÉ's Brendan O'Connor Show, he said he is basing this on findings from a recent medical study carried out in the UK.
"There was a paper published last week from a group in Oxford who looked at healthcare workers who had either previously been infected or hadn't been infected and they followed them over seven months.
"And they found only two people who had previously been infected got reinfected. Those two only had asymptomatic infections. Whereas those who hadn't been previously infected, there were several thousand, a significant number of them got infected for the first time".
He said the take-home message from this study is if you get infected you "have very little chance of getting reinfected, at least for seven months".
"So why vaccinate someone that is already protected?"
He said while there are around 135,000 confirmed cases of Covid-19 in Ireland, he believes there are probably double that as contacts of cases are not currently being tested.
He believes there are probably a quarter of a million people here who have been infected and in a month's time he anticipates that figure could be half a million.
"So if we use two doses, that is a million doses of vaccine that could be saved by not vaccinating those who have recovered from infection."
He said he knows he will get some opposition to this theory that those who recover from Covid-19 are unlikely to be reinfected.
Concerns over vaccine roll-out
His comments come amid ongoing concerns over the supply and roll-out of the vaccine here.
Prof Mills also spoke about the threat of the variants identified in the UK and South Africa, describing them as "worrying" and that transmission may be an issue among children.
However, on a more optimistic note he said "it looks at this stage that the vaccination will work against it."
He also said Ireland's measures for restricting importation of the virus need to be far more stringent.
He believes a negative Covid-19 test result, which is now required for travellers coming into Ireland from the UK and South Africa, should have been made mandatory months ago from everywhere.
"That is what will keep the virus out".
He said it is too late for the variant identified in the UK but the South Africa one where the mutations are more critical, it might make the vaccine less effective so "we want to keep that variant under control".
Separately, the chair of the National Immunisation Advisory Committee said that the current advice is that people who have already tested positive for Covid-19 should get vaccinated.
Professor Karina Butler said that people who have had the infection do not always get good antibody responses and that we do not yet know if that means they are not protected.
"We also know that people can get infected again, albeit not that commonly," she added.
Professor Butler said "it is recommended that they do get vaccinated, but that you leave that until they are recovered from their Covid and for at least four weeks after that".
She said that the advice could change if new evidence emerges.