The BBC has learned that the Northern Ireland school immunisation programme for tuberculosis has been cancelled for the last two years because of a shortage of vaccine.

More than 20,000 school pupils should be given the BCG, to guard against the respiratory disease, each year.

They are normally vaccinated at age 10 or 11.

However, problems with the sole UK supplier, which were expected to last a few weeks, have meant there has been no school vaccination programme for two years.

TB cases

The Department of Health has said it is unhappy at the gap in supply.

There is currently a backlog of about 50,000 children who have not been immunised.

However, it said there was no immediate risk to children.

The number of people treated for TB in Northern Ireland has been steadily falling, but infection is rising in England.

It is more common in other countries including parts of the United States.

For that reason the Department believes it is too early to cancel the immunisation progamme.

Last October, research by the British Thoracic Society (BTS), published in the journal Thorax, said the number of adults and children with TB had hit a 15-year high.

London has more cases of the disease than any other large European city, with more than 4,000 diagnoses a year in the capital.