My Master of Philosophy in Applied Epidemiology (MAE) placement at the National Centre for Immunisation Research and Surveillance (NCIRS) focused on various vaccine preventable diseases from a state, national and international lens.
In response to a rise in invasive meningococcal serogroup W disease in Australia, I performed a comprehensive epidemiological review of the disease. My findings informed the decision of the Australian Technical Advisory Group on Immunisation to support the addition of the quadrivalent meningococcal vaccine onto the National Immunisation Program, providing immunity for meningococcal serogroups A, C, W and Y in infants and young adults.
A small outbreak of varicella among children in an outside of school hours care facility provided the opportunity to conduct an outbreak investigation and a vaccine effectiveness study. Although underpowered, this study demonstrated the occurrence of breakthrough varicella despite high one-dose coverage among primary school-aged children, and evidence for consideration of a two-dose nationally funded program.
I performed another vaccine effectiveness study following a state-wide outbreak of rotavirus in New South Wales in 2017. This was accompanied by an epidemiological analysis of rotavirus notifications and a genetic profile analysis of hospitalised rotavirus cases. The rotavirus outbreak occurred despite high vaccine effectiveness and vaccine coverage. The findings indicated that rotavirus is increasing among the older population who do not have vaccine-induced immunity.
I conducted the first evaluation of the Paediatric Active Enhanced Disease Surveillance (PAEDS) system. PAEDS is an NCIRS-led initiative and actively finds hospitalised cases of serious childhood conditions and adverse events following immunisation. I evaluated this system using a mixed methods study design involving data analysis and stakeholder questionnaires. This evaluation provided practical recommendations for the progression and continuation of PAEDS in a time where the future of PAEDS is unknown.
As part of the international response to the diphtheria outbreak among refugees in Bangladesh, I assisted the response of the World Health Organization in Cox's Bazar. As an epidemiologist, I analysed communicable disease alerts and trends in the refugee camps as well as investigated disease reports and conducted risk assessments. I gained further international experience by assisting in an applied field epidemiology research study: 'Surveillance and Monitoring to Eliminate Lymphatic Filariasis and Scabies from Samoa'. I conducted field visits to dozens of households in remote villages of Samoa to collect mosquitoes for testing the prevalence of lymphatic filariasis antibodies and antigens.
The works within this thesis fulfil the requirements of the MAE. This thesis reports analyses of the epidemiology of invasive meningococcal disease in Australia, vaccine effectiveness of varicella among highly vaccinated children in Brisbane, epidemiology and vaccine effectiveness of rotavirus in New South Wales, evaluation of a surveillance system of serious childhood conditions in Australia, as well as describes the response to a humanitarian emergency in Bangladesh and assistance in a field research study in Samoa. These projects contribute to the work of NCIRS in informing the National Immunisation Program and vaccine policy and practice, as well as to the evidence base of vaccine preventable diseases and international epidemiological research
