Pathogenesis of infection with varicella vaccine

Abstract

The pathogenesis of VZV infection fits best with a dual viremia schema, whereby the exanthem appears after the second viremia. Likewise, features of live varicella (Oka) vaccine virus infection resemble the same pathogenesis model. Comparative electron microscopic studies between wild-type VZV propagated in human melanoma cells and vaccine virus grown in MRC-5 cells indicate that capsid assembly and viral egress differ depending on both the virus strain and the cell substrate. The greatest numbers of aberrant viral particles are seen when vaccine virus is grown in MRC-5 cells. These observations may explain in part the attenuation of the Oka vaccine virus.