Successful infection of the common marmoset (Callithrix jacchus) with human varicella-zoster virus

Abstract

The common marmoset, Callithrix jacchus, can be infected with human varicella-zoster virus (VZV), both wild-type strain KMcC and attenuated vaccine strain Oka/Merck. Infection was accomplished with either whole-cell-associated or cell extract VZV by combined oral-nasal-conjunctival application and was characterized by substantial and persistent anti-VZV antibody responses. The infectivity of VZV for marmosets was destroyed by treatment of inocula with heat or UV light. Diluted inocula with as few as 40 PFU/ml were infectious for marmosets. The lungs were demonstrated to be a major site of viral replication; both the presence of viral antigens and signs of pneumonia were demonstrated in lung tissues. Four serial passages of VZV KMcC were carried out in C. jacchus by a process of in vitro isolation and culturing of VZV from infected lung tissue and reapplication of the cultured isolates to fresh animals. The isolated viruses were identified as VZV both serologically and by restriction endonuclease analyses. The C. jacchus infectivity model should prove useful for determining the efficacy of subunit and live recombinant VZV vaccines as well as for the study of zoster.