A senior HSE official has compared people socialising on the streets over the weekend to V-Day.
It follows gatherings of large crowds in Cork, Dublin and Galway over the past few days.
More restrictions are due to ease this week with the reopening of hotels, while outdoor dining is resuming next week.
The HSE's Chief Clinical Officer Colm Henry says some people have been acting as if the war against covid is over.
"Some of the scenes looked like V-day, in the sense that it was the virus that surrendered.
"This virus doesn't surrender. It exploits complacency, it exploits our weakest position.
"The weakest position is of course those who are unvaccinated, because it's kind of magical thinking to think that if you're not vaccinated you're protected.
"It exploits congested gatherings, and it certainly exploits situations where there's alcohol involved."
