A third of pupils at a County Antrim primary school were absent because of suspected swine flu just before the mid-term break.
Bushvalley Primary School near Ballymoney had 49 of its 152 pupils off on one day - its worst attendance record in 30 years.
Four of the 10 swine flu deaths in Northern Ireland have involved SEN pupils. Some 2,500 children with severe learning disabilities were vaccinated last week, but there are no plans for wider vaccination.
Dr Michael McBride, Northern Ireland's chief medical officer, said: "It's going to be a long and difficult winter. It could be one of the most difficult we've seen." mr.