New data shows Hawke's Bay vaccination rates in 6-month-old babies are on the decline, but improve dramatically when a child reaches 8 months.
Data from March 2019 shows 6-month-olds in Hawke's Bay had a vaccination rate of 70.9 per cent.
This increased to 89.8 per cent by the time a child reaches 8 months old, an improvement of almost 19 per cent.
Nationally, the vaccination rates between 6 months and 8 months only increases 12.7 per cent.
Hawke's Bay District Health Board immunisation co-ordinator Fiona Jackson said the region has many services offering vaccinations.
"These include primary and secondary care providers, Maori health providers, nurse-led clinics and an outreach service.
"More children will be up to date by 8 months of age due to there being a longer time frame to have the 6 week, 3 month and 5 month immunisations completed by this age."
A vaccination rate of 95 per cent needs to be reached for population immunity.
Vaccination rates are declining overall. In December 2015, 6-month-olds in Hawke's Bay had a vaccination rate of 76.6 per cent, compared with 70.9 per cent in March this year.
Nationally the rates were 82 per cent in December 2015 compared with 77.4 per cent now.
Maori children, and children living in areas of high deprivation have the lowest vaccination levels.
In Hawke's Bay, Maori children had a vaccination rate of 69.6 per cent, with Pacific, European and Asian children all having vaccination rates over 80 per cent.
For the quarter ending June 2019, immunisation coverage in Hawke's Bay was 91.2 per cent for children aged 8 months, 94.6 per cent for children aged 2 years and 89.9 per cent for children aged 5 years.
A spokesperson for HBDHB said immunisation statistics change quarterly due to new cohorts of children coming into the age range requiring immunisations per quarter.