Prechallenge antibody responses in SIVΔnef-vaccinated animals.

<p>Concentrations of IgG and IgA binding antibodies to gp130 Env and Gag-Pol antigens in (A) serum and (B) vaginal secretions of all vaccinated animals were measured using ELISA. For vaginal secretions, the specific activity was calculated by dividing the IgG or IgA antibody concentration by the total IgG or IgA concentration in each sample. Shown are geometric means and SEM. The dashed line denotes the cut-off for significance (average specific activity + 3SD for negative controls). (C) The average avidity of Env-specific IgG and IgA antibodies in serum was determined using a NaSCN displacement ELISA. Error bars represent SEM. Mamu-A*01+ animals were found to have anti-Env IgG and IgA antibodies with significantly lower avidity than that in Mamu-A*01- animals. (D) A tissue culture lab adapted (TCLA) SIVmac251 was used to measure 50% neutralizing titers in serum of Grp 5, Grp 20 and Grp 40 animals on weeks 5, 20 and 40, respectively, after SIVΔnef vaccination. No significant differences were observed between the groups.