Varicella zoster virus reactivation episodes and vaccination uptake in Spleen Australia registrants

The Australian National Immunisation Program recently made the recombinant zoster vaccine (RZV), Shingrix, available to First Nations people (Aboriginal and Torres Strait Islander Peoples) aged 50+ years; others 65+ years and immunocompromised people >18 years. It is unclear if people without functioning spleens have a higher risk of varicella zoster virus (VZV) reactivation (herpes zoster, HZ) and are therefore ineligible for the vaccine without meeting other criteria. Spleen Australia has supported people living with asplenia and hyposplenism through education about increased risks of bacterial infection, and advice on vaccines and chemoprophylaxis. To understand the prevalence and predictors of HZ and the uptake of the VZV and HZ vaccines in registrants in July 2023 we offered registrants an online survey. 2657/7624 (34.8 %) eligible persons completed the cross-sectional study, with 1999/2657 (75.2 %) of respondents reported a history of VZV infection and 521/2657 (19.6 %) of HZ. There were 687 self-reported cases with 113/521 (21.7 %) of respondents having >1 episode. Predictors of VZV reactivation were age 61+ years old, splenectomy indication and autoimmune disease. HZ vaccine uptake in eligible age groups (especially 61-70 years old) could be improved, thus highlighting opportunities for further education on the benefits of immunisation against VZV/HZ.