Chief Medical Officer Dr Tony Holohan has urged people to take precautions now, including avoiding crowds and limiting contacts, to avoid being in isolation for Christmas.
In a statement, he said: "Today marks ten days before Christmas. If you contract Covid-19 today your isolation period will include Christmas Day.
"This can be avoided by ensuring you take every step possible to protect yourself."
He advised: "If you are planning to spend Christmas with older family members, anyone immunocompromised or vulnerable to the effects of Covid-19, it is best that you take precautions from today.
"Avoid crowds, limit your contacts, work from home unless absolutely necessary, risk assess your environments and make safe choices over the coming days and weeks.
"Everyone should be aware that Omicron spreads very easily and we have now identified community transmission in Ireland, to the extent that this variant accounts for approximately 13% of all reported cases.
"Taking the opportunity to get a booster dose of vaccination is as vital today as getting the first dose was earlier this year. You will begin to receive the benefit of your booster protection within seven days of receiving your third dose."
Dr Holohan said basic measures to protect people from infection include:
- Practise social distancing
- Work from home, where possible
- Avoid crowds
- Ensure indoor spaces and public transport are ventilated (open windows)
- Hand and respiratory hygiene
- Use face masks
- Stay at home and isolate if you experience symptoms
Today, the Department of Health confirmed 4,235 new cases of Covid-19 and 24 additional cases of the Omicron variant.
There are 470 people in hospital with the disease, down 23 since yesterday, of whom 105 are in ICU, a reduction of four.
There has been a total of 5,835 deaths related to Covid-19 notified in Ireland. This includes 47 deaths newly notified in the past week.
A further 24 cases of the Omicron variant have been detected, bringing to 42 the total number of cases that have been identified following whole genome sequencing.
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The Deputy Chief Medical Officer has said the Omicron variant is spreading rapidly within and between countries.
In a post on Twitter, Dr Ronan Glynn said it is likely that there is a "significant underestimate with community transmission now reported in many countries, including Ireland".
He said data on the clinical severity of Omicron is limited, however he said that there is good reason to believe that a booster vaccine will reduce the risk of becoming very unwell.
🧵⬇️#Omicron is spreading much faster than Delta. This is either because;
— Dr Ronan Glynn (@ronan_glynn) December 15, 2021
A) it spreads more easily from person to person
or
B) it's better than Delta at infecting people who’ve recovered from COVID or been vaccinated (immune evasion)
or
C) (most likely) a combination of a & b
Meanwhile, the Health Service Executive told GPs that they can offer booster mRNA vaccines to all pregnant women aged 16 and older, people aged 40 to 49, and people aged 16-39 in descending order by age cohorts.
Those aged 16 to 29 who got a single dose Janssen vaccine can be offered a booster vaccine in parallel with those aged 30-39.
These groups are the next in priority to those currently being vaccinated, which include adults aged 50 years and older and people aged 16 years and older with an underlying conditions and health staff.
The HSE has said that in order to ensure GPs are able to meet the likely surge in demand for booster vaccines, it will provide them with sufficient amounts of vaccine and consumable stock to run clinics.
GPs with over a thousand patients on their panel will get a grant of around €4,000 to provide Covid-19 boosters under the accelerated vaccination programme.
The payment is mainly to recognise that evening and weekend booster clinics will be needed in many cases over the next four weeks.
The delivery dates of vaccines to GPs starts this Friday and continue on Monday to Thursday of next week, according to the schedule from the HSE.
GPs will also receive a support call from their HSE Relationship Managers over the coming days.
The HSE said GPs will contact their patients to offer booster appointments.
A leading immunologist has said it is imperative as many people as possible get booster doses of Covid-19 vaccine "as a matter of great urgency".
Kingston Mills, a Professor of Experimental Immunology at Trinity College Dublin, said studies from the UK have shown that two doses of AstraZeneca or Pfizer give "limited protection" against the new Omicron variant.
However, he said a third dose "significantly augments that protection" to more than 75%.
Prof Mills said the UK is aiming to have its population boosted by the end of December, but he thinks Ireland will be a bit slower than this.
"I would like to see the booster campaign for the adult population completed by the end of January," he said.
"I think that would be a realistic aim. If we did that it would go a long way to preventing the worst effects of omicron in Ireland."
In Northern Ireland, 2,156 new infections and four further deaths were reported today. There are 315 Covid-positive patients in hospital, of whom 32 were in intensive care.
Covid patients with severe illness frequently male - study
Meanwhile, a new study has reported that Covid-19 patients with severe illness were frequently male, older adults with at least one other medical condition.
It was carried out by researchers at Trinity College Dublin and St James's Hospital.
The overall median length of hospital stay was ten days - ranging from five to 19 days - and was longer in patients admitted to an ICU than in those cared for outside of ICU.
The 28-day fatality ratio was lower in patients in ICU.
Patients admitted to an ICU had a significantly lower probability of death than those who were not.
Professor Ignacio Martin-Loeches from the School of Medicine in Trinity College and Consultant in Intensive Care Medicine at St James's Hospital, said Covid-19 has shown us why critical care is important, but critical care cannot be provided anywhere.
He said critical care is not simply a bed and a ventilator, it needs adequate staff including specialised nurses and doctors and an adequate place to deliver care.
The study represented the Irish cohort in a wider EU project that observed 14,000 patients in 43 countries representing six continents.
