Impact of Australian mandatory policies on immunisation services, parental attitudes to vaccination and vaccine uptake in a tertiary paediatric hospital

Introduction

'No Jab, No Play' and 'No Jab, No Pay' mandatory immunisation policies were introduced in the state of Victoria and Australia nationally in January 2016. They restrict access to childcare/kindergarten and family assistance payments respectively, for under-vaccinated children. We aimed to describe the proportion of attendees to immunisation services of a tertiary hospital, the Royal Children's Hospital Melbourne (RCH), who were motivated by the policies to discuss or catch up vaccination. We also explored the association between policy motivation, vaccine hesitancy (VH) and intent to seek medical exemption, with vaccine-uptake. Referrals to the Specialist Immunisation Clinic (SIC) were also reviewed.

Methods

Parents/Guardians and clinicians completed surveys October 2016-May 2017 from the nurse-led immunisation Drop in Centre (DIC) or physician-led SIC. Vaccine-uptake was measured using the Australian Immunisation Register at baseline, 1 and 7 months post-attendance. The association between vaccine-uptake, policy motivation and VH was explored by logistic regression.

Results

Of 607 children included, 393 (65%) were from the DIC and 214 (35%) SIC. 74 (12%) of parents were motivated by the policies to attend immunisation services and 19% were VH. Only 50% of VH parents planned to catch-up vaccination for enrolment to childcare/kindergarten. Fewer children were fully immunised at 7 months if their parents were VH (difference 18%; OR 0.24, CI 0.1-0.54,p<0.001) or seeking medical exemption (difference 33%, OR 0.08, CI 0.01-0.6, p 0.015).

Conclusions

The 'No Jab' policies motivated attendance to a tertiary immunisation service but children of vaccine hesitant parents and those seeking medical exemption to immunisation were less likely to be fully immunised post attendance, compared to baseline. These data will be used to inform a comprehensive evaluation of the impact of the policies, particularly the educational impact from loss of early childhood education.

Diet-induced obesity attenuates fasting-induced hyperphagia

Obesity impairs arcuate (ARC) neuropeptide Y (NPY)/agouti-releated peptide (AgRP) neuronal function and renders these homeostatic neurones unresponsive to the orexigenic hormone ghrelin. In the present study, we investigated the effect of diet-induced obesity (DIO) on feeding behaviour, ARC neuronal activation and mRNA expression following another orexigenic stimulus, an overnight fast. We show that 9 weeks of high-fat feeding attenuates fasting-induced hyperphagia by suppressing ARC neuronal activation and hypothalamic NPY/AgRP mRNA expression. Thus, the lack of appropriate feeding responses in DIO mice to a fast is caused by failure ARC neurones to recognise and/or respond to orexigenic cues. We propose that fasting-induced hyperphagia is regulated not by homeostatic control of appetite in DIO mice, but rather by changes in the reward circuitry.