Gaps in measles immunisation coverage for pre-school children in Aotearoa New Zealand: a cross-sectional study

Abstract

Aims: To evaluate gaps in measles immunisation coverage for children <5 years in Aotearoa New Zealand.

Methods: In this cross-sectional study, we extracted coverage rates for the first measles, mumps and rubella (MMR1) vaccine and second MMR vaccine (MMR2) from the National Immunisation Register for birth cohorts 2017 to 2020. We described measles coverage rates per birth cohort, and stratified per district health board (DHB), ethnicity and deprivation quintile.

Results: Coverage for MMR1 declined from 95.1% for those born in 2017 to 88.9% for those born in 2020. The coverage for MMR2 was below 90% for all the birth cohorts, with the lowest MMR2 coverage in the birth cohort of 2018 (61.6%). MMR1 coverage was lowest for children of Māori ethnicity and coverage declined over time: 92.8% for those born in 2017 to 78.4% for those born in 2020. Six DHBs had average MMR1 coverage <90% including Bay of Plenty, Lakes, Northland, Tairāwhiti, West Coast and Whanganui.

Conclusions: Immunisation coverage rates for measles are insufficient to prevent a potential measles outbreak in children <5 years. Concerningly, the coverage for MMR1 is declining, especially in Māori children. Catch-up immunisation programmes are urgently needed to improve immunisation coverage.