The study proposes to delineate (a) sites in human beings of earliest multiplication of varicella virus and (b) the use of a primate model infected with a varicella-like simian herpesvirus for directional clues relating to the pathogensis of varicella. Aspects of the study depend on (c) optimal system for recovering virus, and (d) the rescue of the infectious virion from an avid cell association. The primary approaches have been and will continue to be epidemiologically oriented, using exposed children in affected households as subjects. A varicella-like disease has been recognized in, and successfully reproduced in macaque monkeys. In view of difficulties in rescuing varicella virus during the pre- and post-operative stages of varicella we plan to study some of the pathogenetic pathways in the primate model. In view of the avid association of varicella virus with cells, and the desirability of having available cell-free virus for vaccine development, efforts continue to dissociate infectious virus from its cellular milieu. When such dissociation is established quantitative studies of varicella at reduced temperatures become feasible. BIBLIOGRAPHIC REFERENCE: Wenner, H. A., Barrick, S., Abel, D., and Seshumurty, P. The pathogenesis of simian varicella virus in cynomolgus monkeys. Proc. Soc. Exp. Biol. and Med. 150: 318-323, 1975.