Background
On 1 November 2023, the shingles vaccine Shingrix replaced the live vaccine Zostavax on Australia’s National Immunisation Program (NIP) schedule. During 2024, a record number of Australians were vaccinated against herpes zoster. Robust post-market safety surveillance is an essential pillar of vaccine pharmacovigilance, especially during the initial wide distribution of a vaccine. The TGA performed expanded safety surveillance of Shingrix between 1 November 2023 and 30 April 2024.

Methods
TGA expanded safety surveillance activities for Shingrix included reviewing Adverse Events Following Immunisation (AEFI) reports in the TGA’s Australian Adverse Event Management System (AEMS) database and conducting disproportionality analysis reporting (DPAR) to identify potential safety signals. AEFI reporting rates were calculated using Australian Immunisation Register data. Reports of AEFI of special interest underwent detailed review. TGA surveillance reports also considered the results of active surveillance from AusVaxSafety. An independent expert panel, the Vaccine Safety Investigation Group (VSIG), was convened to assess AEFI reports deemed to have the potential to impact public confidence in Shingrix or shift its risk-benefit balance.

Results
From 1 November 2023 to 30 April 2024, the TGA received 631 AEFI reports with Shingrix in adults. 91.9% of reports were described as non-serious. Nine out of the 10 most frequently reported AEFI were expected and listed in the Shingrix product information (PI) document. The VSIG was convened once to discuss a report of meningoencephalitis with Shingrix and also considered the association between Guillain Barre Syndrome (GBS) and Shingrix. Investigations of identified safety signals resulted in Shingrix PI updates, with vertigo and GBS being added as recognised adverse events.

Conclusions
The TGA’s expanded safety surveillance for Shingrix has played an important role in the timely detection, investigation and management of safety signals. Findings were reassuring and contribute to the safety profile of the vaccine.

Shingrix® (GlaxoSmithKline) is an adjuvanted recombinant Varicella Zoster virus vaccine. It replaced Zostavax on the National Immunisation Program (NIP) on 1st November 2023 due to its superior immunogenicity and safety profile. It is recommended as a two-dose schedule, 2-6 months apart, for immunocompetent adults aged ≥50, and immunocompromised adults (or those shortly expected to be immunocompromised) aged ≥18 years to prevent herpes zoster and its complications, including post herpetic neuralgia.

Post-licensure surveillance of vaccines is vital for monitoring of rare, late onset, severe, and unexpected adverse events, and maintaining public confidence in immunisation programs. The Western Australian Vaccine Safety Surveillance (WAVSS) system receives passive reports from individuals and vaccine providers, as well as active reports through SmartVax and data linkage by the WA Health Vaccination Linked Data Repository (VLDR).

In the first year Shingrix was included on the National Immunisation Program schedule (01 November 2023 to 31 October 2024), 144 reports were submitted to WAVSS with 123 reports of adverse events following immunisation (AEFI) and 21 reports of vaccine administration errors. Of these, 71% were reported via passive reporting and 29% via active reporting, including 5% through VLDR. Coadministration with another vaccine occurred in 3% of AEFI reports. The top 10 reported reactions included expected reactogenic symptoms and vaccine administration errors. Severe adverse events included 4 reports of Guillain-Barre Syndrome, one report of encephalopathy, and one report of aseptic meningoencephalitis, all of which were detected through VLDR active surveillance. Two-thirds of the severe adverse events occurred after dose 1. These patients were all offered clinical follow up to discuss their adverse event and implications for future vaccination. Our findings support the favourable safety profile of Shingrix, and the vital role data linkage has in vaccine safety surveillance.

Understanding the short-term safety of newly introduced vaccines for older adults is essential for public confidence, uptake, and post-vaccination care planning. We describe the safety profile of the recombinant zoster vaccine (Shingrix®) and the recombinant respiratory syncytial virus pre-fusion F protein vaccine (Arexvy®) using AusVaxSafety active surveillance data. We analysed adverse event following immunisation (AEFI) reports collected three days post-vaccination for adults aged ≥60 years who received Shingrix between 1 November 2023 and 31 December 2024, and Arexvy between 29 February 2024 and 31 December 2024. The proportions of AEFI reports, medical attendance (MA), and the most commonly reported AEFIs were described. Shingrix data were compared with Zostavax (prior to November 2023), and Arexvy data were compared with high-dose or adjuvanted influenza vaccines administered during the 2024 flu season.

Among Shingrix recipients (N = 120,381, 58% female, median [IQR] age 74 [68, 79]), 47.4% reported AEFIs, with 0.4% seeking medical attention. The most common reactions were local reactions (42.5%), fatigue (28.9%), muscle or joint pain (23%), and headache (17.9%). Compared to Zostavax (13.9% AEFI, 0.2% MA), Shingrix had a higher reactogenicity profile. Among Arexvy recipients (N = 2,395, 62% female, median [IQR] age 75 [70, 80]), 36.8% reported AEFIs, with 0.5% seeking medical attention. Common reactions included local reactions (30%), fatigue (21%), muscle or joint pain (14%), and headache (12%). AEFI and MA reports were higher than that of high-dose or adjuvanted influenza vaccines (15% and 0.1%, respectively).

Both Shingrix and Arexvy demonstrated higher reactogenicity than their respective comparators, consistent with expectations for recombinant vaccines. However, severe AEFIs were rare, and MA rates remained low. These findings support the safety of these vaccines and highlight the need for proactive communication to manage expectations regarding reactogenicity. Ongoing surveillance will be essential to assess long-term safety and inform public health recommendations.

Background
Following the introduction of a funded recombinant shingles (RZV, Shingrix®) vaccination program in people aged 65 and older in Australia, reports emerged of shingles presentations shortly after vaccination. We investigated whether there was an increased risk of shingles occurring immediately post RZV vaccination.

Methods
Two independent datasets—a general practice dataset (Outcome Health’s Population Level Analysis and Reporting) and a statewide hospital and notifiable conditions linked dataset (Vaccine Safety Health Link)- were analysed using self-controlled case series (SCCS) with 21 days post-vaccination as the risk window. The pre-vaccination period only was used as a control to accommodate shingles being both an adverse event and an effectiveness outcome of vaccination. The observation period was 1 January 2023 to 15 September 2024. Adults ≥18 years old were included, with analyses stratified by age (<65 and ≥65 years) and sex. We calculated the rate of incident shingles in time periods relative to vaccination, along with attributable risk and the risk of postherpetic neuralgia (PHN).

Results
We found a 15-fold increase (relative incidence [RI] 15·49, 95% CI 14·46, 16·58, p <0·0001) in presentations of shingles to GPs within 21 days post-dose 1 of RZV vaccination in adults aged 65 and over, with a smaller increase detected in hospital presentations (RI 1·53, 95% CI 1·17, 1·98, p<0·01). Despite this increase in risk in adults aged 65 and over, PHN risk did not increase. No increase was detected in younger adults. Following 21 days, the risk of shingles dramatically decreased in all age groups, reaching an overall 83% reduction following 2 doses.

Conclusions
Shingles presentations transiently increase shortly after dose 1 of RZV vaccination in adults ≥65 years of age, followed by clear evidence of excellent vaccine effectiveness thereafter. While not changing the positive benefit-risk of vaccination, informing recipients of this possibility may support vaccine confidence.

Background
Earlier studies have suggested that infection with ancestral and earlier SARS-CoV-2 variants increased the subsequent risk of developing diabetes. However, evidence on the Omicron variant and the impact of COVID-19 vaccine boosters remains limited.
Methods
A population-based, matched cohort study was conducted using linked data from the AIHW COVID-19 Register. Individuals 16+ years diagnosed with COVID-19 between 15 December 2021 and 31 December 2022 were matched to those without COVID-19 by age, sex, and COVID-19 vaccine recency. The primary outcome was the initiation of diabetes treatment, with negative control outcomes including emergency department presentations for acute injuries and new trimethoprim dispensing. Cox regression with inverse probability of treatment weighting (IPTW) was used to estimate the association between COVID-19 and the outcomes.
Results
There were 5,736,501 matched pairs with and without COVID-19 exposure followed an average of 200 days during which 45,816 initiated diabetes treatment. Individuals with COVID-19 had a 15% higher risk of initiating diabetes treatment (HR 1.151[95%CI 1.136; 1.167]). Higher risk was observed among those hospitalised due to COVID-19 (HR 2.952 [95%CI 2.704; 3.221]) and those who received ≤2 COVID-19 vaccine doses (HR 1.250 [95%CI 1.226; 1.275]). The lowest risk was observed among individuals who received a booster within the past 90 days (HR 1.055 [95%CI 1.026; 1.085]. Negative control outcomes showed a positive association with COVID-19 exposure.
Conclusion
Our findings are consistent with previous research showing an increased risk of diabetes following COVID-19 and further extend the evidence to the Omicron period and show the protective effect of COVID-19 boosters. However, the increased diabetes risk should be interpreted with caution, given analyses of negative control outcomes suggest the existence of potential unmeasured confounding factors.

There is an ongoing need for COVID-19 booster coverage for protection of vulnerable populations. Consumers and vaccine providers require granular information on the impact of adverse events following immunisation (AEFIs) of COVID-19 boosters, to inform community perceptions of vaccine safety and reactogenicity and influence uptake. Online surveys were sent to vaccinees three days post-administration via AusVaxSafety, Australia’s active vaccine safety surveillance system, soliciting reports of AEFI. We report the short-term safety profiles of COVID-19 booster doses administered to Australian adults between 1 January 2023 and 31 August 2024. Bayesian hierarchical modelling was used to estimate the probability of medical attendance (MA) and of experiencing an AEFI after booster vaccination by age, sex, common chronic medical conditions and co-administered vaccines. 433,626 post-vaccination surveys were sent, with 251,949 responses received (58.1%). Overall proportions of reported MA within three days of booster vaccination were ≤1.0% for all vaccine brands (Comirnaty 0.6%; Spikevax 0.9%; Nuvaxovid 1.0%), including when co-administered with either an influenza, pneumococcal (Prevenar 13) or diphtheria-tetanus-pertussis vaccine. Proportions of MA, including routine medical appointments, were ~1% higher in respondents who identified with a chronic medical condition. 5.4% of survey respondents reported any time loss from work or normal activities; of which 14.4% recorded <1 day and 49.6% recorded 1 day. The proportion of respondents who reported any AEFI for Comirnaty, Spikevax and Nuvaxovid were 26.1%, 40.8% and 26.3%, respectively. The most common symptoms were injection site reaction, fatigue and myalgia. Higher risk of AEFI occurred for females compared to males, with an age-dependent risk peaking around 30-40 years of age. The risk of reactogenicity was higher for Spikevax compared to Comirnaty vaccines across all symptoms. Reactogenicity of booster doses was lower compared to COVID-19 vaccine priming doses, with low risk of requiring medical attendance and limited impact on normal activities.

Context: Unidentified cold chain breaches can result in vaccination with potentially compromised vaccines. Responding to these scenarios is challenging for public health units, immunisation providers and consumers. Several unreported breaches have been identified in Perth since 2023.

Aim: To provide timely, evidence-based advice and support to general practices and consumers affected by vaccination during a cold chain breach.

Process: Since November 2023, Boorloo (Perth) Public Health Unit (PHU) and the WA Vaccine Safety Surveillance (WAVSS) system have responded to five large cold chain breaches within primary care. The number of patients vaccinated at each clinic during the breach period ranged from 57 to 675, excluding influenza vaccines. Given these large volumes, Boorloo PHU used automated methods to analyse temperature excursions and assess vaccine viability based on time of administration. An Expert Panel was then convened for each breach to determine specific revaccination advice for affected patients, including infants with multiple affected doses. Advice was communicated to patients via the affected clinic’s staff, with relevant consumer information provided by Boorloo PHU.

Outcome: The proportion of patients who had received at least one vaccine that was considered compromised (based on thermostability guidelines and manufacturer advice) ranged from 27% to 100%, depending on the nature of the breach. All practices have commenced contacting patients to offer revaccination where required. It is challenging for both general practice and public health to respond to these events. Advice developed by the expert panels has now been standardised for most scenarios. Processes to support general practice, including site visits, revaccination plan templates and consumer fact sheets, have streamlined the response. Reflections on successes and lessons learned will be shared.