Isolation of elderly people at Christmas must be considered when deciding to ease lockdown restrictions, a leading member of Nphet has said.
Dr Colm Henry of the HSE said the Government and public health bosses must consider the "sense of isolation and hopelessness" they feel.
While the number of positive Covid-19 cases in Ireland has fallen dramatically, the HSE warned this progress must not be lost.
Asked about the easing of restrictions over Christmas, Dr Henry warned of a resurgence of the virus as seen in Europe.
But he added: "A few months is a long time for the rest of your life for an older person. Particularly if you're very old.
"Christmas is a special time. For some people, it may be their last Christmas.
"So whatever measures are implemented by Nphet or by Government, that protracted isolation for older people, for whom the rest of their lives might mean a much shorter degree of expectation than for younger or even middle aged people, is something they have to bear in mind."
Ireland's reported cases of Covid-19 have fallen dramatically in recent weeks, and is now one of only two European countries with a negative growth in the 14-day incidence rate.
This has led to optimism that level five restrictions can be eased as expected on December 1.
But HSE CEO Paul Reid has warned that the situation could change rapidly.
He said: "We must also remember everything to do with this virus is always very fragile.
"In a short period of time it all can change very quickly. In a short period of time we could find ourselves dealing with a similar trend that we're seeing all over Europe.
"While it is good and positive that we're bucking the trend, we equally know it can turn very quickly. The one proven certainty about the virus is its unpredictability."
"Please don't drop your guard at this stage" he added.
There are currently 370 positive cases in hospital in Ireland, with 40 of those cases in intensive care units.
Of those 370 cases, 17 or 4.6% were in people aged 0-14 years old, 29 or 7.8% were aged between 15-34, while 119 or 32% were 35-64 with 8 ICU admissions in that age group.
The remaining 205 cases, 55.4%, were 65 and over, with 29 ICU admissions.
Dr Henry said that while these are "positive trends", he warned that it could "deteriorate rapidly", citing the situation around Europe.
He told the HSE briefing: "We saw in Ireland and in some European countries during the summer, a feeling that it was gone. It was an indefinite truce.
"We see now the price has been paid, especially in mainland Europe for a suspension, or a kind of magical thinking that the virus had gone away."
He said it was some comfort that Ireland had managed to avoid the worst case scenario seen on the continent for a second time.
But he added: "It is important to remind ourselves how quickly this can deteriorate, as we've seen in mainland Europe.
"Those figures from France are truly shocking, 270,000 cases in one week. A rapid escalation of use of beds and intensive care facilities in France, in well developed healthcare systems.
"175,000 new cases in Italy in one week. In Switzerland, it went from 2,500 cases in mid-September per week to 50,000 cases last week.
"Even if they get their measures right now, we've learned how long that tail is, that when you get it wrong once you're too late, you're living with the consequences for weeks after.
"That's because of the play through to older groups and intensive care."