Northland Health says the meningitis strain that has killed two people in the region is not the one that caused the last national epidemic.
Seven people have been hospitalised with meningococcal disease in Whangarei in the last eight weeks.
All but one were teenagers or young children. Two have died.
Medical Officer of Health Claire Mills says the strain involved is Type C, which is caused by bacteria commonly carried by children and young adults with no ill effect.
She says it's not known why it can sometimes cause serious illness, but it may be because a person's immune system has been weakened by a respiratory infection or other illness.
