There have been 58 reports of measles recorded so far this year, according to the HSE's Health Protection Surveillance Centre.
Two more cases were reported to the HPSC in the past week – one from the Eastern Regional Health Authority and the other from the Southern Health Board.
The two people affected were both female and aged between 15 and 34 years.
The HSE's assistant national director of health protection, Dr Keven Kelleher, has warned that cases of measles are set to rise over the summer.
There has been an increase in measles, an acute viral disease, throughout the world and cases are spreading because people are travelling more.
Dr Kelleher said measles is very active throughout southern Europe.
Current vaccination rates are not good enough currently, with take-up rates up to 8% below what they should in some parts of the country.
The HSE National Immunisation Office is urging people to make sure they are properly vaccinated.
Measles can cause chest infections, fits, ear infections, swelling of the brain and brain damage. The disease is worse for children under one year of age.