Safety of modified vaccinia virus Ankara (MVA) in immune-suppressed macaques

Modified vaccinia virus Ankara (MVA)-based recombinant viruses have been sh own to be potent vaccine candidates for several infectious and neoplastic d iseases. Since a major application of these live, replication-deficient vec tors would be their use in immunocompromised or potentially immunocompromis ed individuals. a preclinical safety study was carried out. Macaques were i noculated with high doses of MVA (10(9)) via various routes. after immune-s uppression by total-body irradiation, anti-thymocyte globulin treatment, or measles virus (MV) infection. No clinical, haematological or pathological abnormalities related to MVA inoculation were observed during a 13-day foll ow-up period. The presence of MVA genomes was demonstrated by nested PCR du ring the course of the experiment in ail macaques. but from none of these a nimals replication competent MVA could be reisolated. These data suggest th at MVA can safely be used as a basis for recombinant human vaccines, and th at it is also safe for use in immunocompromised individuals. (C) 2001 Elsev ier Science Ltd. All rights reserved.