Immunology experts say fully vaccinated people are between five and 10 times less likely to contract Covid, and more than 100 times less likely to die from the disease compared to those who are unprotected.
It comes following reports of a small number of deaths among fully vaccinated people.
Between the middle of May and mid-July, Ireland recorded 70 Covid-19 related deaths.
The Health Service Executive (HSE) recently reported 5% of new virus cases are among those who have received two doses.
New figures yesterday showed 12 fully vaccinated people died from the virus over the last two months, with two of these more than 14 days had passed since they got their second dose.
University College Cork's (UCC) Professor Liam Fanning says while there will be some breakthrough cases, the vaccines offer very high protection.
"We know now from some of the clinical trials data, it gives us large protection against hospitalisation and death," he said.
"It gives great protection and this is the message that has been given and needs to continue to be given across the population while the vaccination program is still rolling out."
Meanwhile, Trinity College Dublin's (TCD) Professor Kingston Mills says there may be small numbers of cases among those protected, but their chances of dying are much smaller than before.
"The death rate has been reduced by about a factor of 10," he said.
"That's because, even though the vaccines are not 100%, protective against infection, they're highly effective at preventing severe disease and therefore hospitalisations and death."
The Health Service Executive (HSE) says it expects Covid-19 cases to reach 2,000 a day in the next week to 10 days.
A further 1,189 cases were confirmed yesterday by the National Public Health Emergency Team (Nphet), while 95 Covid patients are hospitalised, of which 23 are in ICU.
The HSE's Chief Clinical Officer, Dr Colm Henry, says he is preparing for 2,000 cases a day by the end of this month.
"We're certainly expecting it and we're planning for that eventuality in terms of our testing capacity," Dr Henry said.
"Of course, as has always been the case, it's not inevitable because so much is dependent on how much transmission is out there in the community, and that itself depends on how much people heed our advice here to public health advice."
One in every five people currently being admitted to hospital with Covid-19 has been fully vaccinated, according to Dr Henry.
"As a rule of thumb, we're seeing about 20%, which is a surprise," he said.
"I would say, if you look at the totality of people who are totally vaccinated, the vaccination, protects the order of 95% reduction in terms of hospitalisations serious illness and that's holding tight here and abroad."
Meanwhile, Dr Mary Favier, Covid-19 advisor to the Irish College of General Practitioners, says some Covid restrictions may not be eased for "a few months".
Dr Favier says a cautious approach is needed due to the fourth wave.
"The things that are slower to open up are, are the higher risk things where people congregate in bigger numbers, and so they need to hold," she said.
"It's been very difficult for those people who are involved in those areas, but we need to hold a number of weeks or even a few months until numbers are more under control and we can be happy that our vaccination system is complete.
"It could be such a significant amount of time before nightclubs fully open because they're vulnerable in terms of behaviours and very congested."
Professor Philip Nolan, chair of the Irish Epidemiological Modelling Advisory Group, says the current situation is "dangerous" and "very concerning".
He says cases are growing at 6% a day, and they will double every 12 days if this continues.
Speaking on RTÉ radio’s Morning Ireland, Professor Nolan said everyone, as a society, needed to continue to play their part.
There was not a binary point to be reached. A gradual reduction of other restrictions could be looked at as vaccination levels were increased, he said.
Prof Nolan cautioned against looking at what had happened in Scotland recently, where case numbers rose and then dropped. There were always reasons to be optimistic and not to be focussed on the “grim possibilities”, but it was not inevitable that a specific trajectory would occur, he added.
What happened next depended on “what we do for the next few weeks.
The risk to the population (of getting the virus) now was 30% of what it had been, while the risk of serious disease was now ten to 15%, he said.
Professor Nolan called on the public to “get your vaccine when it is offered” and for those who were already vaccinated to support those awaiting their vaccine and support them in efforts to live their lives fully (and safely).
The Delta variant would remain a significant threat for the coming weeks, he said. Everyone needed to continue to pay attention to the basics. He said he had noticed that people were “simply getting too close.”
Some who were vaccinated were “inappropriately feeling bullet proof.” While the vaccine offered protection, the virus could still be transmitted.
An area of Donegal has a rate of Covid-19 that is more than eight times the national average.
Nearly one in every 50 people in Carndonagh local electoral area (LEA) tested positive in the space of two weeks.
On Monday, the country's 14-day incidence rate was nearly 246 per 100,000 people, however, several LEAs are far worse than that.
Carndonagh's was 1,975, by far the highest in the country, while Buncrana has the second-worst rate at 1,238.
Ardee in Co Louth has the third-highest rate, at 774, followed by Galway City Central, with 637, and Donegal Town LEA, with 608.
Internationally, Ireland has the eighth highest 14-day incidence rate in the EU, according to new data from the European Centre for Disease Prevention and Control.
The use of the Moderna vaccine may be extended to include children aged between 12 and 18.
The European Medicines Agency (EMA) is to meet today to discuss whether the Moderna vaccine should be given to children.
The Pfizer vaccine is already approved by the EMA for 12 to 15-year-olds and National Immunisation Advisory Committee (Niac) is currently considering the recommendation.
Dr Anne Moore, a vaccines expert in University College Cork, says it is vital children get a Covid jab as soon as possible.
"In this age group are at the lower end of the group that are showing very strong COVID infections," she said.
"In Ireland at the moment, the vast majority of infections are from 13 to 34-year-olds.
"If the vaccine is safe and efficacious and immunogenic which these vaccines are in that age group, then it's a good idea to vaccinate that cohort."
However, Professor of Immunology at Maynooth University Paul Moynagh says there are some risks to consider.
"When you begin to look at that benefit the risk ratio it certainly does decrease in children, he said.
"The other slight concern is that in some cases been observed that with the RNA vaccines, including the Pfizer vaccine, there is a condition known as myocarditis which is inflammation of cardiac or heart muscle, about one in 20,000, so that has created some concern."