IgM to varicella-zoster virus: demonstration in patients with and without clinical zoster.

Antibody to varicella-zoster (VZ) virus of the IgM type was detected in sera from 50% of persons with clinical zoster, 67% of asymptomatic varicella immunes with a recent intimate exposure to VZ virus and 22 to 40% of varicella immunes with no symptoms of zoster or known exposure to the virus. No VZ IgM was found in newborn sera or in sera from persons susceptible to varicella, demonstrating specificity of the VA IgM assay. Since development of specific IgM is associated with acute infection, these data suggest that reinfection with VA virus occurs and also that antigenic stimulation due to exposure to endogenous VZ virus may occur. We hypothesize that during reactivation of VZ virus, persons with intact VZ cell-mediated immunity (CMI) remain asymptomatic but that those with depressed VZ CMI may develop clinical zoster. These data suggest that there is an unstable relationship between VZ virus and the human host.