The study found that about 80% of Central Coast school entrants were fully immunized. Reliance on immunization certificates as evidence of immunization may overestimate vaccination completion rates, as some certificates may be incorrectly completed. Education of parents, school staff and certificate providers should help to improve both immunization completion and documentation.

Objective: To compare the immunization certificate submission rate for kindergarten school children on the Central Coast of New South Wales for 1994 and 1995; to contact individual parents of children with incomplete or missing immunization certificates by issuing a personalised immunization reminder letter, and measuring their response. Methodology: Seventy Central Coast schools were surveyed. Immunization documentation for 41 77 kindergarten enrolments in 1995 were assessed. Children with incomplete or unknown immunization status were identified. Immunization reminder letters were sent by the schools to parents of the children that were identified. The school recorded any additional immunization certificates submitted. Results: In 1995, 79% of kindergarten children submitted immunization certificates, unchanged from the previous year. Immunization reminder letters were sent to 856 families of children with no certificate and 215 families of children with an incomplete certificate. A further 263 immunization certificates were submitted, representing a 25% response rate. This intervention increased the percentage of kindergarten children with a certificate from 79% to 86%. Conclusions: Education of school staff during the 1994 immunization survey did not change the overall immunization certificate submission rate. Specifically targeting parents through schools can be an effective way of increasing immunization certificate submission.