It has emerged that out-of-date vaccines have been given to children.
The vaccines are given to babies aged 2, 4 and 6 months and a booster is given when the children enter primary school.
However, it is understood that the vaccines would have to be extremely out-of-date to be a cause of concern.
It is likely that parents will be contacted to bring their children back in to be re-vaccinated and a helpline may be set up next week.