The HSE has confirmed the number of cases of measles has risen to 17 in Dublin and Meath.
Of the 12 confirmed cases in the capital, most are in north Dublin, while there is a smaller outbreak of 5 cases in Meath.
The HSE says measles can be a serious illness and is highly contagious.
It's advising people the best protection is to be fully vaccinated with 2 doses of MMR vaccine.
Dr Deirdre Mulholland, Director of Public Health said “The best protection is to be fully vaccinated with 2 doses of MMR vaccine.”
Measles symptoms include:
• High fever
• Runny nose
• Red eyes
• Red rash that starts on head and spread down the body- this normally starts a few days after onset of illness. The rash consists of flat red or brown blotches, which can flow into each other. It lasts about 4-7 days.
• Vomiting, diarrhoea and tummy pain may also happen.
Anyone who develops measles symptoms should avoid contact with others and immediately alert their GP.