Northern Ireland's Health Minister Michael McGimpsey has said he is terribly saddened to hear of the three latest swine flu related deaths in the region.
A second child from a school in Derry has died after contracting swine flu.
Ashleigh Lynch was a fellow pupil of 14-year-old Orla O'Kane from Foyleview Special School, who died last week.
Five Foyleview pupils have now contracted swine flu.
Ashleigh's family said she had brought much joy and richness to her relatives and friends. In a statement they said she was a much-loved daughter, sister, aunt and grand-daughter.
A 62-year-old man has also died in a hospital in the North. He was confirmed as having swine flu but it was not the cause of death.
A third patient with swine flu and other complex health issues has also died in hospital.
News of the latest deaths comes on the day that Northern Ireland's swine flu vaccination programme was launched.
The first batches were given to frontline health and social care staff and those in 'at risk' groups.
About 55,000 doses have been delivered so far and more are due to arrive soon.
Minister McGimpsey said the programme would protect the most vulnerable in society and he encouraged everyone to get it when it was offered.
He also said that starting tomorrow special arrangements were being made to vaccinate children in special schools for severe learning disability as a priority.
Earlier this week, Minister McGimpsey apologised for not informing Orla O'Kane's family that she had swine flu until two days after her funeral.
SDLP Foyle MLA Pat Ramsey extended his sympathies to the family and friends of Ashleigh Lynch.
He said it would be heartbreaking news for the Lynch family and Ashleigh's fellow pupils and teachers at Foyleview Special School and compounded by the tragic death of Orla O'Kane last week.
Mr Ramsey said the wider community would now want to be reassured that all steps were being taken by the Western Health Trust to ensure the school has all the support necessary to help them cope in the difficult days and weeks ahead.
He said the Stormont Department of Health needed to demonstrate that the appropriate procedures had been followed in dealing with this case.
