Abstract
Purpose :
While zoster vaccination is known to reduce the incidence of herpes zoster, few studies investigate its effect on herpes zoster ophthalmicus (HZO). We conducted a retrospective cohort study to examine antiviral prescriptions supplied for HZO treatment as a proxy for HZO incidence, and the number of live-attenuated zoster (Zostavax®, ZVL) vaccinations administered, by age and sex, in Australia’s two most populous states, from 2012 to 2021.
Methods :
Retrospective analysis of individuals from New South Wales and Victoria supplied a prescription with aciclovir or valaciclovir for the treatment of HZO from 2012–2021 (as recorded by the Pharmaceutical Benefits Scheme, a Government-funded universal health scheme subsidising medication costs to Australian residents). Vaccination data were retrieved from the Australian Immunisation Register from 2013–2019. We tracked and compared rates of HZO in the population over time, and between periods of different vaccination strategies.
Results :
There were 33,653 HZO cases (57% female) during 2012–2021. HZO rates increased by 48% from 2012–2015 (relative rate ratio, RR 1.48, 95%CI 1.42–1.53), then decreased by 7% from 2015–2017 (RR 0.93, 95%CI 0.90–0.96), before increasing again by 43% from 2018–2021 (RR 1.42, 95%CI 1.38–1.47) (Figure). From 2018–2021, HZO rates increased in those aged 20–39, 40–59, 60–79 and ≥80 years, by 45%, 41%, 38% and 33%, respectively, but not in those <20 years (RR 1.24, 95%CI 0.96–1.61). Of the 2,613 recorded ZVL vaccinations administered during 2013–2019 to this cohort who had HZO at some time, 11%, 42%, 27% and 18% were in 2016, 2017, 2018 and 2019, respectively.
Conclusions :
HZO rates decreased following the introduction of the ZVL on Australia’s National Immunisation Program in 2016, albeit transiently, and have increased once again. Concerningly, HZO rates in Australia appear to be increasing in those aged >60 years, despite this group being eligible and recommended for vaccination by age, which contrasts with recent data from the United States. Ophthalmologists should encourage vaccination to optimise vaccine coverage, particularly with the recent availability of the more effective non-live zoster vaccine (Shingrix®).
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.