Coronavirus contact tracers are due to carry out backwards tracing, as far back as seven days, from mid-December.
This will see people who contract the virus asked about their movements in the last week, as opposed to the current 48-hour period.
Professor of Experimental Immunology at Trinity College Dublin, Kingston Mills, told The Hard Shoulder this all makes sense.
"I think this is very important because the incubation period of the virus is five days - so you can't assume that you've got the contact only in the last two days."
He said this meant that people could have only had symptoms five days after the initial contact.
"They were missing out on certain contacts by only going back as far as two days.
"Obviously this means that more people will need to be traced, contacted and tested - but it will make it more efficient in terms of finding the sources of the spread of the infection, and then eliminating them from further spread by getting [them] to be tested and isolated."
Prof Mills also said we will have more information on exactly where the cases are coming from.
"Right now we're told that a significant number of the spread is in households - but it doesn't start in the household, it starts somewhere else and is brought into the household".
He said this would be a big help to see what areas are "a consistent source of problem in terms of the spread of the virus".
"This information will provide - as well as actually reducing the number of people that are circulating with the virus - it will provide useful information for the epidemiologists and the public health doctors to tell them where it's coming from".
'This should have been done eight months ago'
He also said he does not understand why it has taken so long to get here - but that it is more manageable than it was before.
"There are significantly less cases now, so there's less tracing to be done per case so that should give them capacity to do it.
"I'm surprised it's taken this long to realise that this should have been done: this should have been done six or eight months ago".
And he suggested this is just one part of increased measures that will be needed, with a resurgence of cases in January.
He said travel over Christmas is likely to be a contributory factor.
"We're in a very good place now, or heading towards a very good place in Ireland in terms of the comparison with other countries in Europe.
"We have much, much more lower levels so we need to keep it there."
