This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Pediatric infection with Neisseria meningititidis remains an important cause of serious illness with neurologic sequellae for which conventional vaccination has been ineffective. Both neutralizing and bactericidal antibodies are protective but the infant immune system does not respond adequately to capsular polysaccharide immunogens. This project tests several meningococcal immunogens formulated with different adjuvants designed to improve the bactericidal antibody response in the infant host. Infant rhesus monkeys, screened for absence of meningoccal antibody and housed in a natural environment, the outdoor field cage, will be immunized with meningococcal vaccines at 3 months of age, followed by a booster injection at 4 months. The titers of bactericidal antibody will be measured in this immunogenicity study.