Perspectives on vaccines against varicella-zoster virus infections

Abstract

Primary infection with varicella-zoster virus (VZV) results in varicella which, in populations where immunization is not used, occurs mostly in children. Varicella is a generalized rash illness with systemic features such as fever and malaise. During varicella, VZV becomes latent in sensory ganglia of the individual, and in 70% it remains asymptomatic for their lifetime. The remaining 30% develop reactivation from latency, resulting in herpes zoster (HZ). HZ usually occurs in persons over the age of 50, and is manifested by a painful unilateral rash that usually lasts about 2 weeks and then may be followed by a chronic pain syndrome called post-herpetic neuralgia (PHN). VZV infections are notoriously more severe in immunocompromised hosts than in healthy individuals. Despite gaps in our understanding of the details of immunity to VZV, successful vaccines have been developed against both varicella and zoster.

Fig. 1

Incidence of varicella in three sentinel counties in the United States from 1995, when varicella vaccine was licensed, until 2000, indicating decrease in the incidence of varicella (Gershon et al. 2008b)

Fig. 2

Case–control study indicating the effectiveness of varicella vaccine over time (Vazquez et al. 2004)

Fig. 3

A FAMA assay, indicating the presence of antibodies to VZV in serum. Unfixed tissue culture cells are incubated first with diluted serum and subsequently with anti-human globulin labeled with fluorsecein isothyocyanate and viewed by fluorescence microscopy (Gershon et al. 2007b)