Fig. 1: Magnitude and durability of antibody responses induced by sequential IDLV-CH505 Env immunizations.

a Non-human primate immunization regimen with sequential IDLV-CH505 Env +/− protein. The dose of IDLV, protein and adjuvant used for each immunization as well as the challenge and necropsy schedules are indicated. A group of eleven animals were sequentially immunized with IDLV-GFP as the control arm. The HIV-Envs encoded by IDLV are the same for all the vaccine groups (A, B1, and B2) and the VSV-G serotypes used for vector pseudotyping are the same for all the groups. b ELISA binding of plasma antibodies to CH505 T/F Env at the peak and six months post-each immunization with IDLV-CH505 (group B1 animals) and IDLV-CH505 + protein (group B2 animals). Binding titers measured as concentration in µg/mL starting at a 1:3000 plasma dilution. The dotted gray line indicates the improved durability of antibody responses at six months post-each IDLV-CH505 immunization. Asterisks indicate that a statistically significant improvement in the magnitude of Ab responses was detected between weeks 24 and 97 (p = 0.0234). c ELISA binding of plasma antibodies to CH505 T/F Env at the peak and six months post-each immunization with IDLV-CH505 (group A animals, safety arm). d ELISA binding of plasma antibodies to the CH505w.136 SOSIP trimer of plasma samples collected after immunization with IDLV-CH505w.136 SOSIP. Binding titers measured as Log area under the curve (Log AUC) starting at a 1:30 plasma dilution. No envelope binding was detected in plasma samples collected before the first immunization. Asterisks indicate that a statistically significant improvement in the magnitude of Ab responses was detected between weeks 101 and 113 (p = 0.0156).