The HSE has warned about the dangers of measles amid a drop in the uptake of childhood vaccinations such as the MMR vaccine.
It is urging parents and guardians to ensure their child's routine vaccinations are up to date.
Recent data from the Health Protection Surveillance Centre shows a "worrying drop in the uptake of childhood vaccines in two-year-olds".
"By the time children reach their second birthday they should have completed their Primary Childhood Immunisation Schedule, including 1st dose of MMR vaccine," it said.
A decrease was seen across all childhood vaccines in Ireland, with the percentage of two-year-olds that have received one dose of MMR vaccine falling below 90%.
Prior to the pandemic period, uptake rates had not dropped below 90% since 2010.
In Area A - Cavan, Louth, Meath, Monaghan and North Dublin - the uptake is even lower than the national rate and significantly lower than the 95% target.
The HSE said this means that many children are not protected from these "highly contagious and potentially very dangerous diseases".
Approximately one in six children aged two in Louth are unvaccinated against measles.
In Meath, Cavan, Monaghan and in North Dublin the figure is approximately one in eight.
The HSE warned that measles is "an acute, highly contagious infectious disease that can lead to serious complications such as ear infections, pneumonia, and inflammation of the brain and even death".
Young children, especially those aged under five, and individuals with underlying immune conditions are particularly at risk.
Although it is usually considered a childhood disease, it can be contracted at any age.
Dr Lois O’Connor, HSE Public Health, urged parents and guardians to make sure their child gets their childhood vaccinations.
"Children who have missed their recommended childhood vaccinations during the pandemic are at risk of catching measles. The MMR vaccines can be given at any age, if missed out during infancy," she said.
"The MMR vaccine is included in the national childhood immunisation programme, and is a safe and effective vaccine against measles, mumps and rubella infections," she added.
"To ensure full protection, two doses are administered to babies and young children with the first dose at 12 months from your practice nurse or GP and the second dose when your child is in junior infants as part of the HSE school vaccination programme," Dr O'Connor said.
