Humoral immune responses. Antibody responses elicited by a single immunization with a recombinant Adenovirus vector construct encoding for HIV-1 envelope protein 3.5 months after transplantation were measured by ELISA for antibody levels to HIV-1 envelope. All serum samples were diluted to find end-point titers and were corrected based on the last dilution of a sample pre-vaccination for each animal. The highest end-point titer for each monkey is depicted in the graph. Animals given multiple doses of KGF are indicated with blue symbols, those given a single dose of KGF with green symbols, and control animals with red symbols. The identifications of individual animals are shown.