The HSE says it's identified patterns of outbreaks in healthcare settings, where the virus was introduced by an unvaccinated staff member.
Vaccine uptake among health care workers is high, but there are some who have reservations and so haven't been vaccinated.
In cases where unvaccinated healthcare workers introduced the virus into a hospital or residential care setting, patients and residents were infected.
Professor Martin Cormican, the HSE’s National Lead for Infection Control says there's little enthusiasm for a mandatory vaccination policy.
There's concerns around the small proportion of children who are vaccinated, with schools to open in the next few weeks.
The Taoiseach warned yesterday that the country hasn't hit the peak of the Delta wave, and will case numbers will likely continue to rise until next month.
Latest figures show a quarter of 12-15-year-olds are partially vaccinated, while 65 percent of 16-17-year-olds have got at least a jab.
Professor Gerry Killeen is a UCC Professor and co-founder of ISAG which advocates for zero Covid.
