Binding ELISA responses to AD-2 peptides at day 69 (A), AD-2 peptides at day 146 (B), and AD169 virions at day 146 (C). Mice (n=10) were immunized with CRM-conjugated AD-2 peptides at days 0, 21, 48, and 110, and boosted with AD169 virions at day 138. Sham vaccine is a saline buffer with alum but no peptide. Sham vaccinated animals were tested against a pool of all AD-2 peptides. All AD-2 peptides were immunogenic and this was sustained and enhanced after boosting with AD169 virions. Antibody titers to AD169 were comparatively low. Error bars represent the SEM.