Around 220 children in west Dublin will need to receive their vaccinations again after it emerged that the jabs may have been incorrectly administered.
The HSE said the vaccines, which are given to babies to protect against serious conditions such as whooping cough, measles and meningitis, may not have been prepared and administered properly by a GP in West Dublin.
The HSE said that it ordered an investigation into the matter following concern expressed by a parent.
The administration of the incorrect vaccines in the practice dates back to the late 1990s.
It said there are no safety issues with the vaccines received by the children concerned, but due to their incorrect administration, the children may not be immune from the diseases against which the vaccines are supposed to protect.
The HSE said it is currently contacting the parents of all effected children and a freephone information line has been set up for them.