Almost everyone is at risk of shingles because they are likely to have been exposed to chickenpox, even if they have no history of clinical chickenpox or chickenpox vaccination. Following chickenpox infection, the virus lies dormant in the nerves near the spine and may re-emerge many years later as shingles. Shingles most commonly affects older adults or people of any age with a weakened immune system.
Zostavax contained a weakened form of the varicella-zoster virus, and as a live viral vaccine, was not suitable for some people with medical conditions or who are receiving treatments that affect their immune system.
Until 2022, one dose of Zostavax was given at age 65 years. It was replaced in September 2022 with a non-live recombinant zoster vaccine, Shingrix.
See Shingrix for zoster vaccine unfunded options from the age of 50 years and from age 18 years if at increased risk of zoster, and funded at age 65 years.
Vaccine effectiveness against an episode of shingles was shown to decrease quickly over the first year after vaccination from around 69% to 50%, and then decreases gradually until effectiveness decreases from around 33% to 17% by the seventh year after vaccination and then decreases to around 4% during the eighth year after vaccination. Although the duration of protection against getting shingles declines, vaccine effectiveness against the severe outcomes of shingles, such as PHN and herpes zoster-associated hospitalisation, remained around at least 50% regardless of age and chronic illness.