Sydney's RPA may have been administering ineffective vaccines to over 500 patients.
Hundreds of patients who were treated at Royal Prince Alfred Hospital (RPA) in Sydney may have been administered ineffective vaccines following the discovery of a faulty refrigerator thermostat which had gone undetected for more than a year.
Over 500 patients, women and babies admitted to postnatal ward 8 East between August 2013 and January this year, were being contacted by the hospital "as a precaution".
The hospital said the refrigerator fault meant three routine vaccines – Boostrix (diphtheria, tetanus and whooping cough), MMR for measles, mumps and rubella and another for Hepatitis B – could have been exposed to temperatures outside the optimum range for storage.
RPA general manager Deborah Willcox said their was no health risk related to receiving the vaccines, dismissing suggestions patients may have contracted the illnesses they were meant to be immunised against.
"However, these vaccines may not provide adequate protection against some illnesses," Willcox said.
"On behalf of RPA, I would like to sincerely apologise for any concern this incident may have caused, or may cause."
RPA general manager Deborah Willcox: patients were being contacted "as a precaution".
NSW Health Minister Jillian Skinner said the hospital's error was "disappointing" and recommended an inquiry to ascertain the issue was not widespread.
"I've asked for a full investigation to take place to see how this could have happened and to ensure that all public hospitals are compliant with medication storage protocols," she said.
"I'm advised measures will be introduced at RPA to ensure this incident does not happen again."
An advisory line, 1800 300 243, has been set up for anyone with immediate concerns.
Royal Prince Alfred Hospital in Sydney.