The Western Health Board has identified nearly 1,500 children who may run the risk of contracting TB following the revelation that faulty batches of BCG vaccine have been in circulation.
More are expected to be identified in the coming weeks as the health board trawls through medical records.
An immediate recall of a batch of vaccines was ordered last month by the Irish Medicines Board as a precautionary measure following tests which showed that one batch was found to be less potent than the one normally administered.
Earlier this month a further five batches were recalled.
The WHB along with all other health boards are in the process of quantifying and identifying those who have received faulty BCG vaccines.
Over 54,000 medical records in Galway, Mayo and Roscommon have been checked by the board to date resulting in the identification of 1,471 patients who received vaccinations from the faulty batches.
Initial estimates indicate that approximately 30,000 people across the State have received vaccinations from the faulty batches.
The health board has said no immediate action is required by those who have received this batch of vaccine.
Appointments will be arranged in the coming weeks for those concerned to attend a health board clinic to establish whether the vaccine was effective. If it emerges that the vaccine was ineffective, people will be offered re-vaccination.
BCG vaccine provides protection against tuberculosis and in Ireland is normally administered to new-born babies and older children.
It is also given to adults who are considered to be at risk of developing TB where potential contact with the disease could occur.
The Department of Health has stated that there is no health threat to persons who received vaccine from the batch concerned other than that they may not have received immunity.
All stock from this batch has been withdrawn and is no longer in use. As a precaution the use of other batches of Evans BCG vaccine, the producers of the faulty batches, have been deferred pending testing and confirmation of their effectiveness.
Alternative supplies of BCG vaccine have been secured and an immediate order is in the process of being delivered to all health boards, and further supplies will be available in September.
Speaking in response to the recall, the Minister for Health, Mr Martin thanked the Irish Medicines Board for their comprehensive response and urged parents to continue to vaccinate their children.
"The immunisation programme currently operated in this country has played a major part in bringing serious, previously common, diseases under control.
"It remains very important that parents continue to have their children protected against the disease concerned."