WHO informal consultation on characterization and quality aspect of vaccines based on live viral vectors, December 2003
Review of vectored vaccines in clinical trials
Immunogenicity testing of ALVAC vaccines has shown that they elicit antigen specific immune responses, including development of neutralizing antibodies, antigen-dependent cell-mediated cytotoxicity (ADCC), lymphoproliferative and CD8+ CTL responses. Compared to attenuated vaccinia vaccines, ALVAC vaccines also have the advantage that their efficacy will not be affected by pre-existing immunity to vaccinia. Currently there are several ALVAC vaccines licensed for veterinary use, e.g., in canaries, horses, dogs and cats with no safety concerns. In addition, several ALVAC-antigen vaccines have been developed that have been or are being clinically evaluated. Many clinical trials have already been conducted in volunteers (over 1,800) with ALVAC-HIV candidate prophylactic vaccines. The latter usually are engineered to express multiple HIV antigens, e.g. gp120, gag, pro (vCP205, vCP1521). No dose response for CTL could be demonstrated with ALVAC-HIV, but repeated immunizations increased the CTL responses.... click on the link below for the full text.