A) Proportion of subjects in each group who had a low (≤1:3200) IgG reciprocal endpoint titer to KEX1 at each visit. Visits 1, 2, and 3 are prior to the first AIDS-defining illness, and visits 4, 5, and 6 are after the first AIDS-defining illness. B) Proportion of subjects in each group who had a high (>1:3200) IgG antibody titer to KEX1 before (Visit 1) and after (Visit 6) AIDS-defining illness. No PcP = group that had an illness other than PcP for their first AIDS-defining illness. PcP = group that had PcP as their first AIDS-defining illness.