Ireland is "rapidly approaching" a scenario where the "phased reopening" of schools is possible, Professor Philip Nolan has said.
He said that the number of cases of Covid-19 could drop to 200-400 cases a day by the end of February if the current progress is maintained.
Professor Philip Nolan, of the National Public Health Emergency Team (Nphet), revealed the new figures yesterday but warned "that there is still a long way to go."
"That is still a pretty high level of disease," he said, but added: "It will allow us to do certain things perhaps."
He pointed out that "we are coming off a very large wave, one so large, I don't think any of us anticipated a wave of disease that big.
"However, what we proved over the last four weeks is something that we knew, that the basic public health measures - reducing contacts, social distance, hygiene - they work against the new variant.
"You just have to work harder at it to prevent viral transmission, and we have done that. I am optimistic about where we will go in March, April, May and June," he told RTÉ's This Week radio programme.
"If we are cautious, I think there are certain high priority, lower risk things that we can do in March, April, May, that will allow us some opening up without a significant increase in the transmission," he said.
In relation to schools re-opening, he said that it was important to realise that schools in their entirety remained open through the October surge of cases.
Separately, Prof Nolan pointed out that: "The number in hospital has fallen significantly, the number in ICU has plateaued, importantly the number of new admissions per day is down.
"Each number is an individual story of suffering and trauma; each admission you prevent is worth the sacrifices you've made."
Dr Tony Holohan, chief medical officer, said: "We have experienced over 1,000 deaths and more than 100,000 cases in January 2021.
"The efforts by all of the population in following the basic public health advice has seen us reduce the incidence of the disease very rapidly compared to most countries in Europe."