Temporal anti-viral IgA in rectal secretions and serum. Data are the specific activity of an anti-viral response (ng of anti-viral IgA per μg of total IgA). (A) Temporal geometric means for anti-SIV Gag/Pol IgA for the different groups. The left hand panel shows data for rectal secretions and the right hand panel, for serum. Closed square, plus GM-CSF; Open circle, minus GM-CSF; Closed triangle, unvaccinated (B) Temporal data for individual animals for anti-Gag/Pol (SIV-239) IgA, anti-gp120 (MN) IgA and anti-gp41 (MN) IgA in rectal secretions. Significant values (mean plus 3 SD of 15 naïve macaques) are highlighted and boxed. One outlier in the unvaccinated controls with constitutive high levels of IgA in rectal secretions is not included in the data set. <, values below the background for detection (0.005 ng of IgA/μg of total IgA); pre, samples taken 2-3 weeks prior to challenge but plotted at the time of challenge; wk, week ; nt, no test; blanks, no sample.