The Health Protection Surveillance Centre revealed the situation after conducting the first nationwide examination of the issue across all schools in the country.
Despite a near-90% compliance rate throughout Ireland, and a four-in-five uptake level in the rest of the HSE South, just one in four children (26.4% 4-in-1 jab; 26.6% MMR) in North Cork are receiving the vital protection.
This is despite the fact that the 4-in-1 vaccine drastically reduces the risk of a child developing polio, tetanus, whooping cough, or diphteria, while the MMR vaccine prevents measles, mumps, and rubella.
The next lowest rate in the country is in Dublin North West, where compliance rates stand at 75.7% for the 4-in-1 jab and 74.5% for the MMR.
The figures are based on a Health Protection Surveillance Centre examination of the success to date of the HSE’s school immunisation programme which took place in the 2011-12 academic year, when 50,210 children were in the targeted age group for the vaccines.
The programme is used to ensure children aged four and five are given both the 4-in-1 jab and an MMR booster shot to ensure they are protected from the conditions.
Under the system, parents are asked to allow their children to receive the shots through their primary schools or their GPs in areas that cannot provide the service within schools.
A high uptake rate protects the individual child and significantly reduces the risk of an infection spreading among classrooms.
While the HSE opt-in system has yet to reach the 95% international standard level put forward by the World Health Organisation, it is proving highly successful.
Nationally, the compliance rate for the 4-in-1 and MMR jabs stands at 86.2% and 83.7%.
This is repeated across the HSE South (82% and 81.6%), HSE West (92.1% and 78.5%), HSE Dublin North East (83.5% and 82.8%), and HSE Dublin Mid-Leinster (89.1% and 89.1%).
In Cork City, compliance rates are also high, standing at 87% and 85.7%.
However, in North Cork — which during the study had 1,472 children in the school age group — the levels were 26.4% and 26.6%.
Irish Patients Association chairman Stephen McMahon said the situation is extremely worrying and must be actively addressed.
“We would be very concerned if immunisations that could save kids’ lives was not being taken up,” he said.
“There needs to be a robust campaign to show parents the evidence clearly supports the need for vaccines, and the clear benefits of receiving the vaccine.”
The Health Protection Surveillance Centre said among the possible reasons for the non-compliance blackspot were parents refusing to let their child receive the vaccine or a child being absent from school on the day of the jab and not attending follow-up clinics. A small number of cases may also be the result of the child receiving the jab privately.
A measles outbreak in West Cork last May saw 25 teenagers contract the condition. None had been vaccinated as children.
Independent medical experts stress the MMR vaccine is completely safe.
It was dogged by controversy after a since discredited 1998 British research paper by Andrew Wakefield and other medics alleged links to autism and led some parents to refuse to allow their children to undergo the jabs.
In 2010, the British General Medical Council found this research to be “dishonest”, while the British Medical Journal described the study as fraudulent the following year.