HUNDREDS of Barnsley children will have to be re-vaccinated - because medication was compromised after being stored in a faulty fridge.
Kids who were vaccinated between January 2009 and June 2014 are being recalled to Brierley Medical Practice.
A letter has been sent to parents warning that whilst being given a vaccine stored at the wrong temperature was not harmful, it may be less effective than normal.
It states staff cannot be certain that children vaccinated throughout the five-year period are adequately protected.
NHS England said a total of 515 children are affected but only 351 are still registered at the surgery.
Those no longer registered at Brierley will receive a letter from their new practice.
Fiona Jorden, consultant in public health for NHS England (Yorkshire and Humber), said: "We would like to offer our apologies for any concern that has been caused to patients and their families by this incident.
"As a precautionary measure and to ensure they have the optimum protection the vaccines have to offer, all affected patients have now been encouraged to make an appointment to receive further vaccinations as required."