BIOLOGICAL AND IMMUNOGENIC PROPERTIES OF A CANARYPOX-RABIES RECOMBINANT, ALVAC RG (VCP65) IN NON-AVIAN SPECIES

A canarypox-based (ALVAC) recombinant expressing the rabies G glycopro tein has been utilized to assess in vitro and in vivo biological prope rties of the canarypox virus vector system. In vitro studies have show n that no replication of the virus can be detected on six human-derive d cell lines, nor can the virus be readily adapted to replicate on non avian cells. Expression of the rabies G can be detected on all cell li nes analyzed in the absence of productive viral replication Analysis o f viral-specific DNA accumulation indicated that the block in the repl ication cycle in the human cell lines analyzed occurred prior to DNA r eplication The exact nature of the block, however, remains unknown. Th e concept of using a non-replicating immunization vehicle has been dem onstrated through extensive in vivo studies in a range of species incl uding non-human primates and humans. The results of such in vivo studi es have exemplified the safety and immunogenicity of the ALVAC vaccine vector.