Abstract
Purpose :
Few population-based studies characterise the incidence of herpes zoster ophthalmicus (HZO), particularly following the availability of herpes zoster vaccination. The aim of this study was to examine antiviral prescriptions supplied for HZO treatment in Australia as a surrogate for HZO incidence between 2016 and 2021, by age group. Australia has no national register recording HZO diagnoses to investigate HZO incidence. In Australia, two zoster vaccinations are available and recommended for individuals aged ≥60 years. Zostavax® (the live-attenuated zoster vaccine) was introduced on the National Immunisation Program (NIP) in November 2016, enabling 70-79-year-olds to receive Zostavax for free. Shingrix® (the non-live subunit zoster vaccine) has been available on the private market since September 2021 but is not funded via the NIP. Zostavax coverage reported to the Australian Immunisation Register for 70-year-olds was 33.9%, 30.5% and 30.4% in 2016–2018, 2019 and 2020 respectively.
Methods :
Retrospective time-trend analysis of antiviral (aciclovir and valaciclovir) prescriptions supplied for the treatment of HZO in Australia between October 2016 and August 2021, recorded by the Pharmaceutical Benefits Scheme (PBS) and Repatriation PBS (Government-funded universal health insurance schemes subsidising medication costs to all Australian residents and veterans, respectively). Poisson models were used to explore annual prescription rates with time, by antiviral treatment and age group.
Results :
HZO rates increased 12% per year in the period 2017–2020 (annual prescription rate ratio [RR] 1.12, 95%CI 1.11, 1.13), rising from 35.5 to 49.3 prescriptions per 100,000 people. The relative increase in HZO rates between 2017 and 2020 was equivalent in those recommended, and those not recommended, to receive zoster vaccination according to age (valaciclovir-treated subgroups), rising 1.47-fold in those aged 61-90 years (RR 1.47, 95%CI 1.41, 1.53) and 1.45-fold in those aged 5-60 years (RR 1.45, 95%CI 1.38, 1.51), respectively.
Conclusions :
These data suggest HZO rates are increasing within the Australian population, including in the age group recommended for vaccination. Ophthalmologists should continue to encourage vaccination to eligible patients, and policymakers evaluate also including Shingrix on the NIP, given Shingrix’s greater efficacy to Zostavax.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.