Transmission levels of Covid-19 remain "frankly far too high" for schools to reopen, the HSE's Chief Clinical Officer Dr Colm Henry has said.

Speaking on RTÉ’s Morning Ireland, he said it is tragic to be talking about school closures again and no one wants to see it protracted because of what children experienced during the first lockdown. 

However, he said, transmission levels are currently ten times what they were in early December. 

He said this needs to reduce to a much lower level "before we can add to additional risk by the mixing of crowds at school settings".

Dr Henry said he hopes there are elements of education that can be looked at more closely, particularly children with additional needs who are much more vulnerable to school closures and "our hope is there would be priority given to certain elements of the education sector".

He said Ireland remains in a "precarious position" and while there is some positive news with falling levels of disease in the community, there are still "extraordinary levels" of infection. 

He said to put that in perspective the average number of cases in the community over the past five days is over 2,500 per day. 

"Those cases have yet to become sick, some will require hospitalisation, some unfortunately will require intensive care and some unfortunately will die", he said.

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Dr Henry said hospital staff remain under severe pressure as they face working double shifts and concentrating on taking care of very ill patients.

He said in some ways it is a "miracle things haven't been worse than they are" in this particular surge. 

He added that there are outbreaks in 29% of nursing homes and 1,800 staff out of the moment, with some nursing homes are requiring support from the HSE and in a small number of cases the Army is providing some support. 

Earlier, Health Service Executive CEO Paul Reid said that 66% of patients - 211 cases - in ICUs around the country have Covid-19.

In a tweet, he also said that 300 people are receiving respiratory support outside of ICUs.

However, the numbers in hospital are starting to decrease and the numbers in intensive care units have plateaued.

Chair of NPHET's Irish Epidemiological Modelling Advisory Group Professor Philip Nolan said last night that the incidence of the disease is now declining by 7% to 10% per day, and at that rate it could be halved in seven to ten days.

But he warned that it will be difficult to maintain that pace, especially since the new more highly transmissible strain of the virus first identified in the UK now accounts for 62% all our cases, and is increasing.

Yesterday, the Department of Health reported 51 new deaths and 2,608 further cases of Covid-19.

There have been a total of 54,318 coronavirus cases confirmed in the last two weeks.

Prof Nolan said the R number (Reproductive rate) is estimated to be between 0.5 and 0.8, but said this is going to be difficult to sustain.

In a letter to the Government last week, Dr Holohan warned that there could be at least 1,000 Covid-19 related deaths in January.

In the letter, dated 14 January, Dr Holohan said modelling by NPHET showed that there could be at least 25-30 deaths a day related to community outbreaks. 

The General Manager of University Hospital Waterford has appealed to the public to abide by public health restrictions after the hospital saw a tenfold increase in Covid-19 cases since December.

University Hospital Waterford had 12 confirmed cases of the virus in mid-December but numbers have been shooting up and reached 123 on Thursday, with at least 25 more suspected cases.

Public urged to follow health guidelines stringently

Meanwhile, a  spokesperson for the World Health Organization said that while new variants of coronavirus do not appear to cause more severe illness, they do seem to be able to transmit more effectively.

Also speaking on Morning Ireland, Dr Margaret Harris said this means people must be even more stringent about following public health guidelines.

"What each country has to do is a full risk assessment, really look at what's going on in their community right now," she said.

"You've got intense, widespread community transmission, so you don't want to be bringing more in because your system at the moment is absolutely stretched. So you do an assessment of that and look for means of not bringing more transmission in."  

She said that while vaccines prevent people from getting sick, it is still not yet known if they prevent transmission of the virus.

"So in other words, the measures need to continue," Dr Harris said. "We will know more about whether or not the vaccine protects from transmission as we follow all the people who have been vaccinated and track all the data."

Ireland has 'lost battle' over new virus variant

The Covid-19 Adviser to Irish College of General Practitioners Ireland has "lost the battle" against the new coronavirus variant first detected in the UK. 

Dr Mary Favier said that "we need to maintain absolute vigilance" about new variants which have been discovered in South Africa and Brazil. 

Speaking on RTÉ's Today with Claire Byrne, Dr Favier said it is "demoralising" and "dispiriting" for healthcare workers to see the number of people travelling into Ireland who are not self-isolating.

She said GPs "on the ground" are seeing evidence that the current rules for people travelling into Ireland are not being adhered to.

Dr Favier, who is also a member of NPHET, said greater enforcement of the current system is required, before the policy of mandatory quarantine is implemented. 

"There needs to be a political will to do that, and it needs to be resourced and funded and stood up as functioning service", she said.

She said the HSE has kept hospital services running "with one hand tied behind their back."

Dr Gerald Barry, Assistant Professor of Virology at University College Dublin, said mandatory quarantine, or very strict regulation to ensure that people are adhering to self-isolation rules, are required if Ireland wants to block new variants coming in.

He said the variant first detected in South Africa is of particular concern as new evidence appears to show that antibodies produced from previous infections are not good at fighting the new variant. 

On PCR testing for passengers, he said: "Having a test 72 hours before you travel to Ireland will pick up a certain amount of people, but it'll also miss quite a large number of people that may potentially be infected after they get their tests, or are maybe infected just before they get their test and then the test won't pick it up. And so they'll happily carry the virus in potentially unknowingly."

He said the testing is not perfect and can miss one in five or six people that are "maybe very early on in their infections. Or maybe slightly past the detection limit but potentially still shedding virus, so the PCR in itself is not perfect."