COMPARISON OF THE EFFICACY OF REPLICATION-DEFECTIVE ADENOVIRUS AND NYVAC POXVIRUS AS VACCINE VECTORS IN MICE

Adenovirus and poxvirus recombinant vectors are more and more used as live experimental vaccines. In order to compare the efficacy of these vectors to elicit serological response and protection against challeng e, two recombinants carrying the same gene (pseudorabies virus gD) wer e used as experimental vaccines in mice, a permissive species to pseud orabies infection. Two routes were tested: intramuscular (i.m.) and in tranasal (i.n.) in order to try to stimulate general and mucosal immun e responses. Several doses ranging from 10(2.9) to 10(8.9) TCID50, dep ending on the vaccines were tested. The estimated log10 (PD50) for the i.m. route were 7.1 +/- 0.2 for the adenovirus vector (Ad-gD), and 7. 6 +/- 0.2 for the Nyvac vector (vP900). For the i.n. route, log10 (PD5 0) of Ad-gD was 7.1 +/- 0.2, and was higher than 7.9 for vP900. While the adenovirus vector proved more efficient than the poxviral vector t o elicit antibody response, only a slight difference was observed when comparing the survival times of animals after challenge. Adenovirus w as found better only for the 10(7.9) TCID50 dose, when inoculated i.m. Intranasal vaccination appeared efficient only with the adenovirus ve ctor for the TCID50 10(8.9) dose. Copyright (C) 1996 Elsevier Science Ltd.