Immunisation coverage in Christchurch in a birth cohort. Christchurch Immunisation Coordination Committee.

AIM: To ascertain the immunisation status of a birth cohort of infants at 8 months of age. METHODS: Data on all children born in Christchurch in June, July and August 1995 were matched with immunisation benefit claim information for the 6-week, 3-month and 5-month immunisation events. Those not listed as receiving all three immunisations by the age of 8 months were traced to ascertain their immunisation status. RESULTS: Immunisation status was established for 933 (93.1%) of the cohort of 1002 infants. Of these, 95% had received all three immunisations that were scheduled up to 5 months of age. This represents a coverage of at least 88.2% of the entire cohort. It was probable that many of those not traced would also have been fully immunised. Using a conservative estimate of coverage among this group, we calculated that 93% of the entire cohort had been fully immunised by the age of 8 months. CONCLUSION: There was a high immunisation coverage rate in Christchurch. This is in contrast to a commonly held view that children in New Zealand have a poor immunisation record. There was no evidence of a significant anti-immunisation stance among Christchurch parents. Immunisation data relevant to specific, defined populations can identify individual children and groups of children who may require assistance beyond general practitioner recall to achieve appropriate immunisation. The tracking process also allowed for immunisation reminders to be personally delivered and included some facilitation for achieving further immunisation. We suggest that a pilot programme, using a centralised register based on birth data, feeding into existing immunisation delivery and recall systems, and using tracking methods similar to those used in our study, should be the next step in addressing immunisation coverage surveillance and immunisation coordination in Christchurch.