The Ministry of Health recommended children have a dose of the MMR vaccine at 15 months and a second dose at 4 years old.
The outbreak had mainly affected young people because many children missed out on their second vaccination in 2001 when the age of the second jab was changed from 11 to 4.
The now-discredited MMR controversy from 1998 onwards may have also affected immunisation rates, according to the Auckland Regional Public Health Service.
According to national immunisation data, the coverage rates in young children up to the age of 12 years were about 80 per cent. Today's mid-20-year-olds had even lower rates, with a national coverage survey reporting that only 60 per cent of Pakeha children were fully immunised in 1991, with lower rates for Maori (42 per cent) and Pacific children (45 per cent).
Waitemata DHB paediatrician Dr Tim Jelleyman urged parents to make sure their children's immunisation was up to date.
"The only way to be sure your child is protected from needless suffering and the risk of potential hospitalisation is to have them immunised."
Anyone who does not have a record of whether their children have received the two doses should have them vaccinated anyway as there is no health risk associated with a third dose, according to the Ministry of Health.