Northland District Health Board is closing in on its target of vaccinating 85% of tamariki and rangatahi against Meningococcal C.
It launched an immunisation programme following a community outbreak of the disease, which can cause an infection around the brain and blood poisoning, and lead to death or permanent disability.
Friday this week is the final day of the Board's free vaccination programme, and the board has brought in All Black Sonny Bill Williams to spread the word about getting inoculated.
He says children who aren't immunised and become infected with Meningococcal C, can lose their limbs and their hearing.
Sonny Bill says about 7000 children and teenagers in Northland need to get immunised.