In 2024 immunisation coverage for First Nation infants in SESLHD declined from 91.4% to 83.3% demonstrating a clear need to address access to immunisation. Sydney Children’s Hospital in partnership with the SESLHD PHU, undertook community engagement and worked with Aboriginal healthcare providers in the La Perouse area. Several barriers to immunisation were identified for the local community including: transport issues; out-of-pocket costs to see general practitioners (GPs) and limited availability of GP appointments; alongside Medicare registration delays and vaccination concerns. Importantly, a need for a trusted Aboriginal health worker (AHW) to assist with reliable information around vaccine safety was highlighted as a key need to increase uptake of immunisation for First Nation infants.

In response, we established a fortnightly outreach clinic at La Perouse Community Health Centre that provides immunisations and education on timely vaccine administration. Collaborating closely with AHWs and community services to enable a culturally-safe approach to care, initiatives including available parking, flexible appointment options, SMS reminders, and a “no Medicare, no worries” policy were incorporated to the model.

We also implemented a nurse-initiated medication (NIM) protocol for prescribing and administering paracetamol, allowing authorised nurse immunisers to administer paracetamol prior to meningococcal B vaccination – including a take-home bottle for additional paracetamol doses. This has increased uptake of meningococcal B vaccines.

Sometimes it’s just about having a yarn, focusing on relationship building—listening to families, addressing concerns, and fostering trust. This was particularly apparent during the rollout of the RSV nirsevimab program.

Since April 2024 we have had 113 direct interactions with children and families, with strong ongoing engagement. Further collaboration with the PHU is ongoing, including commencing a whole family model of care to provide immunisations for all ages.

The program reflects our commitment to improving First Nations immunisation rates through education, collaboration, and culturally-sensitive care. Through continuous feedback and partnership, we aim to share lessons to actively reduce the barriers to immunisation for First Nations children and build a foundation for better health outcomes for the community.

Note: Permission to publicise this service has been obtained from the La Perouse Aboriginal Health Centre and the PHU.

Background: Immunisation coverage among Aboriginal children in Perth is among the lowest in Australia with notable gaps in coverage at both 12 and 24 months of age. Aboriginal children are at higher risk of acquiring a vaccine preventable disease and more likely than non-Aboriginal children to present to hospital for these diseases. Barriers for Aboriginal Australians in accessing healthcare include logistic barriers and the availability of culturally safe services. Evidence shows that home visiting interventions, while resource intensive, improve access and vaccination coverage.

Program: Boorloo (Perth) Public Health Unit implemented a home visiting vaccination service in 2018. The home visiting program is now offered 3 days per week to families of Aboriginal children up to 24 months of age who are overdue for immunisation but are unable to access a healthcare provider. Vaccination is also offered in childcare and community centres for some families. Contact is made with families by an Aboriginal Health Liaison Officer (AHLO) and home visits are attended by the AHLO and immunisation nurse.

Outcomes: In 2024, the Boorloo PHU AHLO contacted 902 families whose children were overdue for immunisation up to 24 months of age. Many children were overdue for multiple schedule points and also had overdue siblings. Contact attempts were successful in 82% of cases following up to three attempts. A total of 298 home visits were conducted in 2024 with 341 vaccine encounters, including opportunistic vaccination of family members. Of all overdue children identified, 2.9% of families stated that they did not want to vaccinate their child. Families included in the program often have significant other life challenges and in-home support is generally very well received.

Conclusion: A home visiting service is a culturally safe alternative for overdue Aboriginal children and is well utilised and well received by families. It resulted in opportunistic vaccination of household members.

Community consultation: Aboriginal Principal Project Officer (WA Department of Health), and the Boorloo PHU, Aboriginal Health team support the publicising of the outcomes of the Moorditj Kids program.

Background: Delayed vaccination is more common among Aboriginal children and leads to delay in the receipt of subsequent vaccines. Evidence supports the effectiveness of reminders for Aboriginal families, particularly when undertaken in a culturally appropriate manner by Aboriginal Health Workers (AHW) and combined with practical supports.

Program: The Boorloo (Perth) Public Health Unit (PHU) Moorditj Start program commenced in March 2023. It comprises an early intervention phone call from a Boorloo PHU AHW to all families of Aboriginal infants in Perth at 5 weeks of age. The call provides the opportunity to discuss immunisation and support to book appointments. Transport assistance is offered, and home visits are available for families who cannot access a clinic. Ongoing reminders are provided by SMS or phone at each immunisation schedule point and families can opt out at any time.

Outcomes: From 1 March 2023 – 31 December 2024, 1,710 infants were included in the program. At 5 weeks of age, successful contact was made with 69% of parents/carers, with further attempts leading to 79% success by 6 months of age. Of those contacted successfully at 5 weeks, 26% requested that the Boorloo PHU AHW link them with a service provider of which 82% requested the AHW book the immunisation appointment on their behalf. To date, 88% have received DTPA 1 6-8-week vaccine on time, compared to 64% of those who could not be contacted and 82% received MMR on time compared to 76% of those who could not be contacted. Calls are well received by families and assistance with booking and transport was considered helpful.

Conclusion: An early phone call from an AHW to carers of 5-week-old Aboriginal infants was an effective and well received intervention to promote timely immunisation uptake in Perth. The program continues to operate in 2025.
Community consultation: Aboriginal Principal Project Officer (WA Department of Health), and the Boorloo PHU, Aboriginal Health team support sharing the outcomes of the Moorditj Start program.

Background: In Australia, human papillomavirus (HPV) vaccination is routinely offered to adolescents aged 12-13 years, primarily through schools. Until recently, it comprised two doses. Before the COVID-19 pandemic, Australia achieved high HPV vaccine coverage with closing equity gaps over time, but coverage declined during the pandemic and has continued falling, with widening equity gaps, since. In February 2023, Australia moved to a single-dose schedule, which should have increased coverage. However, this has not yet occurred. Evaluating the shift to a single dose is crucial to identify implementation challenges and their impact on vaccine coverage. We aimed to explore program perspectives on the transition, how the broader context influenced implementation, and lessons learned.
Methods: In September 2024, we interviewed 11 state and territory senior immunisation program staff online about their experiences implementing the change to single dose HPV vaccine in the school-based program. Interviews were approximately 60 minutes duration. Group analysis identified categories and themes.
Results: Analysis identified post-pandemic changes to routine program operations and how the change process was managed. Factors that aided implementation included centrally produced communication resources and well-established communication channels with parents and providers; challenges included the short lead time to implementation, inability to change existing processes quickly, and difficulty maintaining multiple school visits. Analysis also identified broader factors that influenced implementation, including post-pandemic parental hesitancy, lower school attendance, staffing challenges and introduction of electronic consent.
Conclusions: In this presentation, we will discuss some of the reasons why, a year after implementation, simplifying the HPV vaccination schedule may not have had the intended positive impacts on vaccination coverage. We will discuss implementation challenges and the influence of external factors, as well as lessons learned from the implementation and areas that require ongoing support and improvement.

Background: Herpes zoster (HZ) is a viral disease impacting patients quality of life due to pain and rash. It is a vaccine-preventable disease with approximately 15 million cases observed annually in individuals ≥50 years of age (YOA) worldwide. Recombinant zoster vaccine (RZV) has proven effective in protecting against HZ infection. This is the first study evaluating the potential increased (incremental) public health benefits - in terms of HZ cases averted - of vaccinating adults ≥50 YOA worldwide with RZV.

Methods: A previously published static multi-cohort Markov model with an annual cycle length, and a lifetime horizon was used, which incorporated the following inputs : population estimates, and age-gender specific mortality rates from the latest (2022) United Nations data, depicting populations on December 31, 2023; HZ incidence rates from a recent (2021) meta-regression analysis of HZ burden across the globe (Asia, Europe, Northern America, and Oceania); RZV efficacy modelled based on 11-year clinical trial follow-up data [NCT02723773].

Results: Assuming a 70% second-dose completion rate in the general population ≥50 YOA worldwide, absolute increases in uptake of RZV by 5% would reduce the number of expected cases by >10 million over the remaining lifetime of vaccinated individuals. Numbers needed to vaccinate (NNV) to avert 1 HZ case by age group worldwide varied from 9 in 50-59 YOA to 18 in ≥80 YOA, and 10 overall in ≥50 YOA. Variations observed by region and age reflected varying inputs, i.e. population demographics, HZ incidence rates, life expectancy and vaccine efficacy.

Conclusion: Even with a relatively modest increase of coverage rates worldwide, RZV is projected to prevent millions of HZ cases due to the long-term protection it affords. Lower NNVs are observed in younger vaccinated cohorts, irrespective of region, outlining the relative merits of age of vaccination.

Funding: GSK (VEO-000923); Encore from IDWeek 2024

Background and Objectives:
The suboptimal vaccination rates seen among the elderly population in China highlight the pressing need for immediate intervention to expedite the immunization campaign and alleviate the repercussions stemming from the termination of the Zero-COVID strategy. Fewer studies identify vaccine hesitancy using machine learning techniques. To research the proper parameters for predicting and assessing vaccination hesitancy and discover the best results using machine learning techniques, this study takes data from a sizable cross-sectional study in China.
Methods:
From January to March 2023, we conducted a cross-sectional survey at community health centers across 15 provinces in eastern, central, and western China. A total of 647 adults aged ≥60 participated. We applied LASSO regression and Random Forest (RF) algorithms for variable selection and model construction, respectively. We then used SHAP (SHapley Additive exPlanations) to interpret the relative contribution of each predictive factor in an interpretable ML model.
Results:
Over half of respondents (53.32%) reported vaccine hesitancy, with a mean age of 68 years. Of the original predictors, 11 were statistically significant in LASSO. The RF model showed strong performance (AUC=0.800) in classifying vaccine hesitancy. SHAP analysis revealed that higher levels of confidence, collective responsibility, fear of COVID-19, prior vaccination status, and certain regions were associated with reduced hesitancy. Conversely, constraints, complacency, lower education levels, and poorer health status increased hesitancy risk.
Conclusions:
This study offers robust and trustworthy evidence regarding the factors that contribute to vaccine hesitancy among the elderly population in China. It is noteworthy that this study is the first attempt to employ ML algorithms for constructing a predictive model for COVID-19 vaccine hesitancy in the elderly population. Furthermore, the findings are elucidated through the utilization of the visualization SHAP algorithm, which enhances the credibility of quantitative evaluation and the formulation of tailored interventions aimed at mitigating vaccine hesitancy among the elderly population.

Background: Population-based data on the prevalence of risk factors for vaccine preventable diseases (VPDs) are essential for informing immunisation policy development. Prevalence estimates by selected individual risk-factor conditions for viral respiratory VPDs are available in published data from national health surveys. However, these conditions quite commonly occur as comorbidities in older persons. We aimed to estimate the cumulative prevalences of individuals with at least one of these conditions in the Australian population.

Methods: Data on participants’ self-reported chronic medical conditions from the 2017-18 National Health Survey (NHS) and 2018-19 National Aboriginal and Torres Strait Islander Health Survey (NATSIHS) were sourced from the Australian Bureau of Statistics. Using a published method (with more details to be presented), those coded medical conditions were best matched to the set of shared major medical risk conditions associated with severe influenza, respiratory syncytial virus (RSV), and COVID-19, as stipulated in the Australian Immunisation Handbook. The cumulative prevalence of at least one of the included conditions within each age and population stratum were calculated.

Results: Among non-Indigenous adults, for age groups of 18–34, 35–49, 50–64, 65–74, and ≥75 years respectively, the estimated cumulative prevalence of risk conditions was: 3.8%, 8.0%, 21.5%, 35.8%, and 43.0%. For Aboriginal and Torres Strait Islander peoples, the estimates were 7.4%, 28.2%, 51.4%, 59.5%, and 55.9%, respectively, for these age groups. These estimates were broadly comparable to findings in the previous ABS 2011–2012 NHS and 2012–2013 NATSIHS, using the same method though with minor differences in algorithms for inclusion of medical conditions.

Conclusion: Our method enables the estimation of the national cumulative prevalence of medical conditions associated with several viral respiratory VPDs, using data from two Australian health surveys. These national-level estimates, not readily available without dataset linkage, are crucial to inform risk-based immunisation strategy deliberations.

Background
Hepatitis B virus infection is a global health problem. Successful vaccination response is achieved in about 95% of the immune-competent population.The vaccine to prevent Hepatitis B is typically administered in three doses with an additional fourth dose, intradermal dosing or a repeated higher dose regimen is given to those that fail to show immunity. Despite these additional regimens, some remain vulnerable to hepatitis B and are deemed non-responders.

Individuals with immune compromise have the highest likelihood of non-response. Various strategies have been developed to elicit an immune response in these individuals with some success. One of these alternative strategies, using the combination Hepatitis A & Hepatitis B vaccine may show an improved response. In a study by Cardell,three doses of combined hepatitis A and hepatitis B vaccine to 44 patients, who had been previously non-responsive. Approximately 95% showed an immune titre > 10 mIU/mL. This suggests hepatitis A antigen may act as an adjuvant and enhance immune response.

Method
An audit was commenced in June 2024 at Monash Health for immune compromised Hepatitis B non-responders, who had previously completed a full course of Hepatitis B vaccines followed by re vaccination. These patients were offered a combined Hepatitis A & Hepatitis B vaccine on an accelerated and shortened schedule, four weeks apart. Hepatitis B serology was checked four weeks later to ascertain an immune response.

Results
To date a total of 36 patients have been enrolled in the project. 18 renal patients and 18 infectious disease patients. Each of these patients have previously completed up to 3 full courses of Hepatitis B vaccine, using various vaccine strategies and have not previously seroconverted. To date, 10 patients have completed the two doses of Twinrix and had serology 4 weeks later All 10 patients have now seroconverted to Hepatitis B.

Conclusion:
Every effort should be made in high-risk populations to vaccinate against this virus. Immunity is looking promising with the combined Hepatitis A & B vaccine.. The data in this abstract will be updated following expansion of the project with external grants being sought.

Background
The Assisted Vaccination Clinic (AVC) at The Children’s Hospital Westmead has been operating for over a decade, providing an individualised multidisciplinary vaccination service for children who are unable to be vaccinated in the community. Over this time the immunisation schedule has changed, and practices have been modified. We aim to review the AVC service so that it can be better understood weather there are interventions which are associated with greater or lesser success in vaccination amongst this population.

Methods
From 30 June 2015 to 31 December 2024, children who presented to the AVC at the Children’s Hospital at Westmead were included. Study data was extracted from electronic medical records and entered into a REDCAP database. Long term follow-up of patients who had reached 17 years of age was conducted by reviewing their vaccination status recorded on the Australian Immunisation Register.

Results
137 participants were enrolled in the study, over 183 clinic visits. The median age was 13.3 years (IQR 1.6 years) and the most common comorbidities reported were needle phobia 142/183 (77.6%), autism spectrum disorder 64/183 (35%), and anxiety 44/183 (24%). Of the visits, 89/183 (48.6%) involved a patient with >1 underlying medical condition and 151/183 (82.5%) visits resulted in successful vaccination of the patient. By 31 December 2024, 53/137 (38.7%) patients had turned 17 years of age, of which 36/53 (67.9%) were up to date with their immunisations.

Conclusions
The AVC is a valuable resource which has been able to vaccinate children who would otherwise remain unvaccinated, with a high success rate. The proportion of children who attended clinic and remain up to date with the immunisation program aligns with vaccine coverage rates (65%) for this age group across the Australian population.

Respiratory Syncytial Virus (RSV) is a leading cause of hospitalization amongst young children in Aotearoa New Zealand (NZ). An antenatal RSV vaccine and monoclonal antibody (mAB) injection are used overseas and may soon be introduced in NZ. To inform a future roll-out, our study explored healthcare professionals’ (HCPs) and pregnant people’s knowledge, perceptions, and recommendations regarding RSV prevention. We employed a convergent parallel mixed-methods design and were guided by a study Advisory Group. A cross-sectional survey was undertaken with 200 HCPs and data were analyzed using Stata. Preliminary findings indicate that most HCPs (79%) had a good understanding of RSV and its severity. Most HCPs (n=157; 79%) thought there was a high need for an antenatal RSV vaccine and 147 (74%) ranked it as their preferred option. Safety and efficacy of the preventative options were their top concerns. Most HCPs recommended information pamphlets for families and training modules for HCPs to support the roll-out. A qualitative interpretive descriptive methodology guided data generation among pregnant people (n=13) in Auckland and Dunedin. With a focus on equity, we recruited people who are pregnant or have recently delivered who self-identified as Māori, Pacific, or an ethnic minority migrant. A directed content analytic approach was used to construct categories. Participants preferred the option that would be most protective for their infant for the longest time. Recommendation from trusted HCPs and access to clear information from credible health authorities would encourage uptake, though some needed reassurance about safety. Accessible, trusted, and safe administration venues would be critical to supporting vaccine or mAB acceptance. These findings shed important insights to inform a comprehensive and inclusive roll-out programme to support equitable access to preventative options to reduce the risk of RSV.

Microbial genomics is a powerful tool that helps us better understand infectious diseases, improve public health surveillance, strengthen public health decision-making, and design vaccines and other treatments. During the COVID-19 pandemic, microbial genomics was essential in detecting SARS-CoV-2 variants of concern, informing public health policy and guiding Australia’s response.

On 7 January 2025, the Australian Health Protection Committee endorsed the National Microbial Genomics Framework for Public Health 2025-2027 (the Framework). This Framework builds on the first National Microbial Genomics Framework 2019-2022 to provide a consistent, national, and strategic view for integrating microbial genomics into the Australian public health system, and for identifying microbial genomics policy issues and challenges that need to be addressed. In this iteration, the Framework incorporates implementation activities to cover the period of 2025-2027. The Framework contains updates which reflect a logical progression from the previous iteration’s implementation activities, and alignment with the Interim Australian Centre of Disease Control’s (CDC) strategic direction, including:
• updating the Framework to reflect the landscape of microbial genomics post-COVID-19
• adding One Health-related implementation actions, and
• aligning with the Interim Australian CDC’s preliminary data strategy.

The Framework reinforces the Interim Australian CDC’s collaborative commitment to integrating microbial genomics into the Australian laboratory and public health system. This will ensure this technology is effectively used throughout Australia, enabling Australia to better respond to public health threats.