A vaccine that protects against tuberculosis will not be available again in Ireland until later this year or early next year.
Minister for Health Leo Varadkar said production difficulties, delivery delays and sealing problems had resulted in the BCG vaccine, which is produced in Denmark, not being available.
Mr Varadkar gave his explanation in a response to a question from Sinn Féin TD Gerry Adams.
Mr Adams raised the issue after Sinn Féin County Councillor for Louth Jennifer Green, who is due to give birth in three weeks, had been told her baby would not be administered the vaccine as recommended by the Health Service Executive.
Mr Adams said the difficulties had been known by the Department of Health since last year but despite this, it had failed to identify an alternative supplier to provide that vaccine in the short term.
He said that, as a result, at least 50,000 babies, and potentially many more, would not receive their BCG when appropriate.
In a statement, the Department of Health said other countries are experiencing similar delays in acquiring supplies of the vaccine from the Danish company - the only licensed supplier of the vaccine in the EU.
The statement added that production was suspended in 2014 pending an extensive investigation regarding a possible problem with the capping of the vials.
It added that the investigation has now been concluded and product produced during 2014 is being released, but it will take some time to release all the batches produced.
The statement also said the HSE will arrange appointments for children to attend clinics when the vaccine supply is restored.
The HSE said in a statement it has "no control over when BCG vaccine will be delivered by the vaccine manufacturer" and that "these supply issues will continue until at least Quarter 1 2016."
The statement said the HSE National Immunisation Office has been in regular contact with the manufacturer of BCG and with the Health Products Regulatory Authority (HPRA) who licenses vaccines in Ireland as well as with other relevant stakeholders.
The statement added that the number of TB cases in Ireland has been falling and that there were no cases of the virus in young children in 2014.
Councillor Green said she does not accept the Government’s excuse for a delay in the supply of the BCG vaccine and that other options should be made available for parents who wish to have their babies immunised.
Speaking on RTÉ’s News at One, Councillor Greene said it is quite worrying that the minister for health could not give a definite time frame as to when the vaccine would become available again.
She said she is worried that the health of babies will be in danger if they do not get it.
Councillor Greene added that it is worrying for parents who have babies, who have not had the vaccine and live on farms, as cows carry the disease.
She said Sinn Féin has asked the minister for health to look into another supplier and that she is awaiting a response.
She said there is currently no other option in the country available to parents who want their babies vaccinated.
Ms Greene said her concerns are not alarmist and that outbreaks of TB do happen in Ireland. She said there has been no outbreak recently as vaccines have been available.
"The HSE have on their website currently, it's advised that all babies of two months to three months be vaccinated against TB and get the BCG vaccine.
“So I don't know why the Government are suddenly turning around when they don't have the supply and saying...we don't need it. We do need it," she said.