Chickenpox

Purpose of review Varicella-Zoster virus (VZV) remains a public health issue around the globe despite the availability of a live attenuated vaccine and several highly acive antiviral agents. A program of universal infant vaccination against vericella was introduced in the Us almost 10 years ago. Epidemiological data continue to accumulate that will inform decision-making on vaccine use elsewhere. These findings, together with relevant advances in VZV virology, form the substance of thisw review. Recent findings Understanding of the pathogenesis of vericella has significantly advanced with demonstration that the cation-independent mannose 6-phosphate receptor is critical to both entry and egree of enveloped VZV. While our knowledge of intervening events remains sketchy, the future study of VZV will be facilitated by the recent successful cloning of the VZV gemone into a bacterial artificial chromosome. Models of latency an reactivation are also being developed, which may help us to underdstand the epidemiology of herpes zoster in vaccinated populations. Continued evidence of decline in the incidence of varicella, associated hospitalizations and deaths suggest that the vaccine as used in the US is highly effective. However, rates of breakthrough disease are significant and sufficient to sustain outbreaks, even among highly vaccinated populations. This is so despite the generally reduced infectiousnouss of varicella occuring in vaccinated individuals. There is some evidence of attrition of the immune response over time following immunization in a small proportion of vaccines. Summary Our ability to prevent and treat vericella still outstrips our knowledge of pathogenetic and immune mechanisms. Further clinical advances are likely to arise from growing understanding of VZV biology.