The Irish government on Monday cancelled this year's St Patrick's Day parade in Dublin and around the country on medical advice because of the coronavirus outbreak.
The annual parade celebrating the country's patron saint regularly attracts hundreds of thousands of people to the Irish capital and was to have been held on March 17.
Last year an estimated 500,000 people attended the event. Irish media reported around 100,000 attendees were overseas visitors.
But the government moved to cancel the festivities because of fears over the spread of COVID-19.
Ireland currently has 24 confirmed cases according to department of health figures released Monday night.
"On the advice of NPHET (National Public Health Emergency Team) today (Monday), the Saint Patrick's day festival across the country has been cancelled," said Prime Minister Leo Varadkar.
"This is nationwide, not just in Dublin," he told a news conference.
The government said in a separate statement the decision was based "on the unique nature and scale" of the festivities, as well as continued transmission of the virus.
"The situation in relation to other events and mass gatherings remains under review," it added.
"There's a lot about this virus that we don't yet know, but it is possible that we're facing events that are unprecedented in modern times," warned Varadkar at the press conference.
"We have no treatments, no vaccine, and no immunity, so this is as much going to be a society response... as it is going to be a medical response."
Earlier, Ireland's second city, Cork, announced the cancellation of its St Patrick's Day Parade after conducting a risk assessment based on World Health Organization recommendations.
Cork City Council said it was "not in a position to provide the necessary assurances in relation to current WHO guidelines".
St Patrick's Day parades were previously cancelled in 2001 during an outbreak of foot and mouth disease.
Ireland's Six Nations rugby union fixture with France in Paris was postponed earlier on Monday, after the French government banned all public gatherings of more than 1,000 people.
Another scheduled fixture in the tournament between Ireland and Italy in Dublin was cancelled last month on public health grounds.
Irish budget airline Ryanair meanwhile announced the suspension of internal flights to and from virus-hit areas of northern Italy and a reduction in international flights to the zone.