Nine deaths and a further 443 confirmed cases of Covid-19 were reported on Tuesday.
The Health Protection Surveillance Centre (HPSC) said three of the deaths were in January, two in February, three in March, and one this month.
Those figures bring to 4,727 the total number of deaths in the Republic while case numbers climb ever closer to the quarter million marker, now at 238,907.
As of 8am on Tuesday, 261 people were in hospital with the virus, of which 60 were being treated in ICU. There were 12 additional hospitalisations in the preceding 24 hours.
Of the new cases reported, 75 per cent were in those under 45 years of age with a median age of 31. Men accounted for the majority at 239, while 203 were among women.
As usual, Dublin accounted for most cases at 208, followed by Cork (32), Kildare (24), Meath (20) and Donegal (17), with the remaining 142 cases spread across 19 other counties.
In the last week, there were just short of 116,000 tests carried out with a positivity rate of 3.1 per cent.
As of April 3rd, 932,324 doses of vaccine have been administered and of those 660,800 were first doses and 271,524 second doses.
In Northern Ireland three more people with Covid-19 have died and an additional 57 people tested positive for the virus in the past 24 hours, the North’s Department of Health said on Tuesday.
Fuller details will be available on Wednesday, when the department’s Covid-19 dashboard is updated after the Easter holiday period.
Earlier on Tuesday, a professor of immunovirology said figures showing 0.1 per cent of Covid-19 cases in the State come from outdoor transmission may be an underestimate.
Prof Liam Fanning of University College Cork said he was surprised by the figures and felt there could be a "slight bias" in the Health Protection Surveillance Centre (HPSC) data on cases linked to outdoor transmission.
Figures from the HPSC showed just one confirmed case of Covid-19 in every thousand is traced to outdoor transmission.
Of the 232,164 cases of Covid-19 recorded in the State up to March 24th this year, 262 were as a result of outdoor transmission, representing 0.1 per cent of the total, the data revealed. There were 42 outbreaks associated with outdoor gatherings, with one community outbreak accounting for seven cases.
Speaking to Newstalk Breakfast on Tuesday, Prof Fanning said there was an obvious difference in transmission rates of the virus between outdoor and indoor locations.
He cautioned that meeting people outdoors still posed a risk, as the virus could be spread if someone infectious was “face-on chatting” to other individuals.
People should try to avoid speaking directly face-to-face and instead attempt to speak to each other while side by side when outdoors, a common method used during the Spanish flu, he said.
Prof Fanning said financial support to encourage more outdoor dining spaces should also be “much higher”, given the low transmission rates outdoors.
At present, restaurants, cafes and bars are restricted to delivery or takeaway services only, with no outdoor dining permitted.
The Government plans to invest €17 million in upgrades for local authorities and businesses to help create outdoor dining spaces.
Under a new scheme, businesses will be able to apply for grants of up to €4,000 each to invest in outdoor seating and other amenities.
International data
Orla Hegarty, assistant professor of architecture at University College Dublin, said the Irish figures on outdoor transmission were not robust but they were in line with data from other countries. She said a study in China found that only three out of 1,200 cases examined were transmitted out of doors.
She told RTÉ radio 1’s Today with Philip Boucher-Hayes that “outdoor events need a lot of protection around them, people need to realise that close conversations can be high risk, that sharing a car or a taxi or a bus to get there can be very high risk.
“We need to be careful about it [allowing outdoor events], but I think the science is there now to support it, but it’s also a really good clue about how we make indoors safe.”
Epidemiologist Patricia Kearney told the same programme that finding out where someone got infected is “much more difficult” than discovering who they passed the virus on to.
“What we’ve been doing to date [with contract tracing] is when we think about Covid, we think about transmission chains and we’re interested into whom somebody has passed the infection on to,” Prof Kearney said. “In the reverse, we’re actually asking different questions – so what we’re asking is where did that case get the infection from?
“It’s not just about finding the sources, it’s really doing an investigation – public health risk assessment to try and figure out is that where the infection could have arisen. It is positive that we’re starting to do that but it really requires the kind of expert local knowledge that exists in our regional departments of public health, so I think it will be quite some time before we get to resolve some of the mystery surrounding some of the community transmission.
“In Australia they use the term ‘mystery cases’ for community transmission and I think it is quite a useful way of thinking about the challenge,” Prof Kearney said.
Hospital patients
There were 263 patients in hospital with Covid-19, as of 8pm on Monday, according to the Health Service Executive’s (HSE) daily operations report.
Fifty-five Covid-19 patients were in intensive care units, compared with 65 seven days ago.
There were 320 positive cases of Covid-19 reported on Monday, and no deaths related to the virus, according to the National Public Health Emergency Team.
The HSE expects to surpass the milestone of administering the one millionth Covid-19 vaccine dose in the Republic this week.
In a post on Twitter, Minister for Health Stephen Donnelly said Ireland was making "huge progress" tackling the pandemic.
Mr Donnelly said one in six adults had received at least one dose of a Covid-19 vaccine and the country had “one of the lowest rates of Covid-19 in Europe” at present.