More than 97% of people in Australia are seropositive to varicella-zoster virus (VZV) by 30 years of age,16 even if they cannot recall having varicella at a younger age.
Adults who are VZV-seronegative on laboratory testing and have no history of age-appropriate varicella vaccination may receive either:
2 doses of varicella vaccine (this is preferable — see Varicella), or
1 dose of Zostavax (if aged ≥50 years)
In some small studies, high-dose VZV-containing vaccine (comparable to Zostavax) was given to healthy VZV-seronegative adults and previously infected adults. The limited data suggest that Zostavax was well tolerated and immunogenic in seronegative people, but the incidence of self-limited injection site reactions may be slightly higher than in seropositive people.17,18
There are no specific studies of Zostavax safety in VZV-seronegative adults who have mild to moderate immunocompromising conditions. A cautious assessment of risk factors — both underlying disease and medications — is required in these adults.
