The Republic of Ireland is facing a lockdown that could last into March, with officials believing it is "inconceivable" that the mutant strain of Covid found in England is not already on the island.
Tanaiste Leo Varadkar signalled that while the restrictions would be reviewed on January 12, the lockdown was likely to continue until spring.
"It's difficult to speculate about the timeline, but I think it'll probably be towards the end of February or early March before a critical mass of the population is vaccinated," he said.
"I think we need to operate on the basis that these restrictions may well be in place until that happens, although we will review the situation on January 12.
"Perhaps we'll be able to get some positive decisions about January, but I think we should all operate on the basis that these restrictions will be in place for the first two months of next year."
Mr Varadkar hinted, however, that some businesses could be ordered to remain closed until next summer.
He said reopening grants would be available "in the spring or summer" to help companies "when we're in a position to tell them that they can reopen".
It comes as new Covid-19 infections doubled in the space of just one week, with Mr Varadkar warning of "exponential growth".
It is expected that new cases will exceed 1,000 a day before Christmas and could hit 2,000 a day before New Year's Eve.
Taoiseach Micheal Martin said health officials viewed it as "inconceivable" that the new strain of the virus found in England was not already in Ireland and behind the rapid rise in cases.
"While we do not yet have firm evidence that the new, more virulent strain of Covid is in our country, the rate of growth tells me that the safest and most responsible thing to do is to proceed on the assumption that it is already here," he added.
The Irish Cabinet decided to re-impose level five restrictions from Christmas, with all restaurants and gastropubs to close by 3pm on Thursday. Schools will re-open as planned after the Christmas break and most retail outlets will be able to stay open.
However, the requirement to stay within your own county comes back into force after Christmas, with people allowed to travel beyond their county until the end of Boxing Day.
If people are staying in a different county over Christmas, they are allowed to stay on at that location, but there must be no new inter-county travel once they return home.
Home visits from two other households remain in place to the end of Boxing Day. Then a rule of only one other household will apply to the end of the year. From January 1, no visitors are permitted in private homes or gardens, except for care reasons.
Christmas Day religious services can still take place, but they must return online thereafter, although places of worship may stay open for private prayer.
While non-essential retail will be allowed to remain open, there will be no post-Christmas sales. The Irish government will today tell the National Retail Forum its reasoning, which is to prevent crowds in city and town centres.
"No sales events will take place. People shouldn't be rushing to the shops and it shouldn't be crowded in the shops over the next few days. We're relying on retailers to make sure that isn't the case," Mr Varadkar said.
Robin Swann advised the Executive on Monday night that a travel ban could have "serious adverse implications" on the financial viability of aircraft and ferry routes, leading to a knock-on effect on the supply chain of essential goods and services.