Tailoring the Australian vaccine barriers assessment tool (VBAT) for Aotearoa New Zealand: Using a local equity...

There is need for international tools to measure and monitor childhood immunisation programme uptake, validated specifically for local country context. Childhood vaccine coverage has declined in Aotearoa New Zealand (ANZ) since 2016, especially for Māori and Pacific Peoples.

To adapt the Australian Vaccine Barriers Assessment Tool (VBAT) for ANZ context, to support improvement of vaccination coverage, particularly for Māori and Pacific Peoples children.

The NZ VBAT was developed and validated in three stages: (1) Literature review and cognitive theory, refined through cognitive testing in ANZ. (2) Surveys assessing reliability of potential items and selection of items via expert consensus. (3) Surveys assessing predictive validity of future immunisation, with responses linked to vaccination records. Confirmatory Composite Analysis (CCA) assessed fit of the final preferred models.

Stage 1 identified 80 items, refined to 45 through cognitive testing. In stage 2, 467 surveys assessed item reliability. In stage 3, 314 out of 492 (64%) carers/parents (82% Māori and Pacific Peoples) completed the final 35 item survey, with 176 responses linked to immunisation records. Logistic regression showed strong associations between access and acceptance barriers and vaccine uptake. The final 6-item short survey had five domains encompassing safety, access, effectiveness, intention and influence; whilst the 14 -item long survey incorporated two additional domains: social responsibility and relationship with provider. Both surveys outperformed the US Parent Attitudes Childhood Vaccines (PACV) Survey, explaining 13% and 14% of uptake variation compared to PACV's 10%.

The NZ Vaccine Barriers Assessment tools (NZ VBAT) is a culturally appropriate tool to identify the social and behavioural drivers of suboptimal vaccination in children <5 years in NZ. It will support development of targeted interventions to achieve optimal immunisation coverage and reduce equity gaps.