Almost 20,000 new Covid cases were confirmed in Ireland today as the new BA.2 variant drives a surge in infections.
The figure is made up of 9,324 positive PCR tests and a further 10,542 antigen results registered through the HSE portal.
Meanwhile there are 1,466 people in hospital with Covid, of which 55 are in ICU.
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The highly infectious BA.2 strain of Covid, which is considered to be a subvariant of Omicron, is being blamed for the current surge.
Also known as 'stealth', it is 30% more infectious than Omicron - which is already 70% more infectious than the previous strain of coronavirus.
Top immunology Prof Luke O’Neill has said it’s the most infectious stain yet.
He told the Irish Mirror: "That level of spread is very high for any virus, so other viruses that spread like wildfire would be measles, that's really infectious, and it's going in that direction.
"So it could turn out to be highly infectious, in terms of the league table of infectiousness, it's right up there.
"It's the most infectious SARS‑CoV‑2 we've seen, for definite."
It comes as the public are being reminded of Covid symptoms.
It is not clear whether there are specific symptoms associated with BA.2 that differ from earlier strains, however a recent ZOE Covid Study found dizziness and fatigue among the commonly reported symptoms of ‘stealth’, with other signs said to be a runny nose and a headache.
Prof Luke O’Neill said that it appears symptoms can manifest more quickly - usually in two days compared to four - but can be less severe and disappear sooner.
"The question now is if GPs see someone come in with BA2 will they notice a slight difference?" he said.
"Overall, it's similar, there's some evidence of more stomach problems or more gastrointestinal disturbances, but that hasn't been linked directly to BA.2 yet, that's just an assumption.
"What we do know is it grows more quickly, so the incubation time is shorter with it, so what that means is when it goes into your body, within two days you're getting a peak of virus in your body.
"Whereas with BA.1, with Omicron and the previous ones, that was about four days.
"So you see now people are picking it up and within two days, they're spreading it and getting symptoms more quickly and that creates problems for obvious reasons because it spreads more readily as a result of that.
"We may see different symptoms then because it's growing much faster in people."
Meanwhile Dr Tony Holohan has stepped down as Ireland’s Chief Medical Officer after two decades.
He has been in the role at the Department of Health since 2008 and is stepping down to take up a new job as Professor of Public Health Strategy and Leadership at Trinity College Dublin from July.
Announcing the news, Dr Holohan said: “It has been a great privilege for me to serve as Chief Medical Officer and to have had an opportunity to be directly involved in issues of great importance and relevance to the health of the people of Ireland.
“In particular, these past two years have presented extreme challenges to public health globally and I have been honoured to work alongside exceptional colleagues in the Department of Health, the HSE, the wider health service and across Government. “During this time, I have witnessed the dedication of colleagues to protecting the health and wellbeing of people across Ireland.
“I am very excited by this new opportunity, and I look forward with energy and enthusiasm to working with the Provost of Trinity College Dublin and her team, and through this to continue to contribute to improving public health policy, practice and outcomes.”
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