The Chief Medical Officer has appealed to people with foreign holidays planned to cancel their flight and hotel bookings.
The National Public Health Emergency Team's noticing a "worrying trend" of Covid-19 cases increasing, and new clusters emerging.
Some last week resulted in the need to test over 20 people as close contacts of individual cases.
No new deaths linked to the virus have been reported - but 24 more cases have been confirmed, bringing the total to 25,462.
Dr Tony Holohan wants people with summer holidays planned to reconsider.
Dr Holohan said: "We would like people not to travel. Yes and for some people, people will have made bookings and I think it makes much more sense to not go ahead with that booking than to risk travelling abroad and picking up this infection.
"The risks for you, for any family members that are travelling with you or indeed any close contacts you would have when you come back, and then the risk that represents for us as a community and as a society.
"I think that would be not just in your individual interest but in our collective interest."