"Prioritise who you need to see.''
The National Public Health Emergency team has warned that everyone needs to reduce their contacts, particularly those living in Waterford, Louth, Cork, Kildare, Wicklow and Galway.
The warning comes after it was confirmed that Donegal will become the second county to enter level 3 restrictions from midnight tonight.
Louth and Waterford have so far avoided moving to level three despite being close to or above 100 cases per 100,000.
Acting Chief Medical Officer (CMO) Dr Ronan Glynn said gatherings and celebrations such as significant birthdays, communions, weddings and garden parties involving extended families and close friends have been a significant factor in outbreaks.
"I'm asking people everywhere, but particularly in Donegal, in Dublin and more broadly in Louth, Kildare Wicklow Waterford, Cork and Galway to pay particular attention to the public health authorities.
"Prioritise who you need to see, limit the size of your social network," he said.
"I do not want to be back here next week or the week after," Dr Glynn told a press briefing after the Cabinet accepted NPHET advice to introduce further restrictions in Donegal.
"Keep your distance, wear face coverings and don't go to work, don't send your children to school, don't interact with others if you have any symptoms".
This was echoed by Taoiseach Micheál Martin who said "there is every chance we could have similar announcements in other areas."
''Unfortunately the virus doesn't discriminate.''
Meanwhile, communions, christenings, weddings, funerals and travel across the border are being blamed for one area of Donegal having the highest Covid-19 incidence rate in the country.
Member of NPHET Dr Mary Favier says the surge of cases in Donegal can be traced back to such gatherings.
''You can understand in a way why this happened, in a sense people see these as very special events in a child and a family's life'', she said.
''And they make exceptions for them, they justify them to themselves and say well it's only the neighbours from across the road, it's only the aunties.
''And unfortunately the virus doesn't discriminate, whether it was a communion party or a house party''.
