A decline in varicella but an uncertain impact on zoster following varicella vaccination in Victoria, Australia.

Varicella vaccine was licensed in Australia in 1999 and publicly funded in 2005. We examined trends in varicella and zoster hospitalisations and community consultations in Victoria during periods of no vaccine, private availability of vaccine and funded vaccination. Varicella hospitalisation rates declined 7% per year (95% CI 5-9%) from 2000 to 2007, predominately in children under five (12% per year, 95% CI 9-16%). A similar decline was seen in community data. The zoster hospitalisation rate increased from 1998 to 2007 (5% per year, 95% CI 3-6%), before introduction of varicella vaccine. Among those aged 80 and over the hospitalisation rate increased 5% per year (95% CI 3-7%) from 1998 to 2007. Zoster increased in community data from 2001.