Ireland has suffered its saddest day in the fight against the coronavirus with a record number of 17 deaths and 325 new cases of the infection.
The mounting death toll from the virus has now reached 71.
It comes as Irish patients with Covid-19 are to take part in an international clinical trial to see if there are treatments which can support those who are critically ill with the virus.
Of those who have died in Ireland from Covid-19, more than eight in 10 were over the age of 70 and two-thirds were from the east of the country.
Some 54 had reported underlying health conditions and 59 died in hospitals.
The jump in new cases brings to 3,235 the number of people struck by the infection so far.
It comes as hospital intensive care units are also coming under more intensive pressure, caring for 113 severely ill patients with the virus.
So far 703 people have been hospitalised and around half of people have picked up the infection without knowing the source.
Junior doctors in St James’s Hospital in Dublin are also being rostered to work 24-hour shifts to provide care to patients with the virus.
One-quarter of all those infected are healthcare workers. One in four of the 647 healthcare workers including doctors, nurses, healthcare assistants and porters who were infected in a hospital or a healthcare setting.
The median age of the latest victims of the virus was 84.
The Health Research Board said it is to start a clinical trial in a number of intensive care units to find out if there are treatments which can support patients who are seriously ill.
The trial will start enrolling Covid-19 patients on the island of Ireland at the start of this month and will test interventions in critically ill patients, capture the outcomes and analyse data across an international network in a global effort to reduce the impact of the virus.
If a patient is too ill to consent to taking part, their next of kin may be asked for permission.
Rapid data sharing will ensure that findings relevant to the Covid-19 outbreak are shared quickly with others working in the area to inform decision-making. It will start in St Vincent's Hospital and University Hospital Galway and will also involve Beaumont Hospital in Dublin, Cork University Hospital and University Hospital Limerick, as well as the Royal Victoria Hospital in Belfast.
Chief Medical Officer Dr Tony Holohan warned that while the emergency measures were flattening the curve, the 15pc daily rise in cases - although down from 33pc - was still too high.
The fear is that there will be a surge in cases in the coming weeks which will overwhelm hospitals with seriously ill patients.
The National Public Health Emergency Team, which met yesterday, is now recommending more intensive tracing of the contacts of people who test positive.
Dr Holohan said in future "contact tracing will encompass the period from 48 hours prior to the onset of symptoms" because the person who tests positive may not have been showing signs of the infection.
The average number of contacts of people who are infected has reduced to three due to physical distancing and these tend to be others in the household, he added.
They also want safeguards to be stepped up in nursing homes and other residential centres where residents have been at the centre of clusters of the virus.
There have now been 23 outbreaks or clusters of the virus in nursing homes.
The moves include asking healthcare workers who share a house or an apartment to agree to go to other accommodation which could be provided by the HSE as a means of reducing the chances of them infecting each other and passing it on in the workplace.
"The measures that we have recommended today should significantly enhance the preparedness and response to cases and outbreaks in nursing homes and other residential settings," he said.
"As we have said from the beginning, our efforts must be focused on protecting the most vulnerable to Covid-19 and these recommendations announced today seek to achieve this."
Dr Holohan said the HSE would be working with the homes in areas of staffing and equipment.
It is understood the patient safety watchdog Hiqa will work with some homes to assess their infection control procedures.
Dr Cillian de Gascun, of the National Virus Reference Laboratory, confirmed there can be a delay of 10 days before a person who is tested for the virus gets their result.
It means priority groups such as people with severe illness, healthcare workers and people who have had contact with a positive case are facing delays.