It's unlikely that fresh COVID-19 restrictions will be introduced but the possibility can't be ruled out, according to Dr Mary Favier.
It comes as new cases continue to rise, with the five-day moving average of new cases just below 3,000.
Chief Medical Officer Dr Tony Holohan yesterday said a so-called 'circuit breaker' lockdown is not being considered at the moment.
However, NPHET has urged people to cut down on their social contacts in a bid to reduce the spread of the virus.
Dr Favier - a member of NPHET and COVID advisor to the Irish College of General Practitioners - told Newstalk Breakfast she "fears" COVID restrictions could be inevitable if case numbers continue to rise.
She said: “Restrictions are unlikely but can’t entirely be ruled out.
"Other European countries are looking at them again this week… it will come down to what we do now.
“It’s so depressing to think about it - none of us have the stomach to go back. We need to find ways to work around this.
"We are victims of our fragile health service, which has been underfunded and under-resourced over the years.”
Dr Favier said GPs are noticing there's a "lot of COVID activity" in the community.
She observed: “There’s some concerns among GPs about people presenting with symptoms - either looking for notes off work or antibiotics - with no consideration it may be COVID, and very resistant to getting tested.
“They’re people ringing from work, ringing from the supermarket.”
Dr Favier said fatigue is understandable, but people are being asked to “dig deep” again as Ireland faces a fresh surge.
She stressed the situation is completely different to last Christmas due to vaccination, but the concern is now that non-COVID care is getting delayed or postponed due to the increase in hospitalisations.
She noted that the seven-day average of COVID-19 new cases is up 49% since last week - showing "how rapidly" virus rates can increase.
