A Sydney hospital has begun contacting hundreds of women after discovering a faulty fridge may have ruined vaccines given to new mothers.
Nine newborn babies were also immunised with vaccines that may not work.
The Royal Prince Alfred (RPA) Hospital at Camperdown, in inner west Sydney, said the affected vaccines did not pose a direct health threat but their effectiveness may have been compromised.
The problem relates to patients who were on the hospital’s 8 East postnatal ward after August 2013.
RPA general manager Deborah Willcox said 570 mothers were being contacted about vaccines for diseases including diphtheria, whooping cough, tetanus, measles and mumps.
All of the affected babies were given vaccines for hepatitis B.
She said the vaccines may have been exposed to slightly higher temperatures than normal, but mothers should not be alarmed.
“It is very important that I state there is no risk associated with receiving potentially less effective vaccines,” she said.
“Due to an issue with the refrigerator’s thermostat, the vaccines may have been exposed to temperatures just outside of what would be the acceptable, optimal temperature ranges for these types of medications.
“We cannot absolutely guarantee their effectiveness.”
The hospital has set up a free clinic at Croydon Community Health Centre to provide re-vaccinations to women free of charge.
RPA director of public health Leena Gupta said she expected many women would need to be vaccinated again.
“The bulk of the vaccines were given to the mothers,” she said.
“One was Boostrix to protect against whopping cough and another vaccine called MMR which prevents measles, mumps and rubella in future pregnancies.”
Ms Willcox said the incident was being investigated.
“There is no question this is incredibly disappointing for us,” she said.
“We are confident all our refrigerators are working and are now functioning as they should.”