Safety of and Immune Response to a Human Parainfluenza Virus Vaccine (rHPIV3cp45) in Healthy Infants

Inclusion Criteria for All Participants: * Good general health * Full term infant, born later than the 36th week of pregnancy * Has received age-appropriate inactivated or subunit routine immunizations at least 2 weeks prior to study entry * Has received age-appropriate live routine immunizations at least 4 weeks prior to study entry and at least 2 weeks for rotavirus vaccine * Available for the duration of the trial * Parent or guardian reachable by telephone for post-immunization contact * Parent or guardian willing to provide informed consent * For Group 2 participants, serum hemagglutination-inhibiting (HAI) titers to HPIV3 of or less than 1:8 Exclusion Criteria: * Known or suspected impairment of immunologic functions. Infants who are HIV infected, who are bone marrow or solid organ transplant recipients, or who are using immunosuppressive therapy, including systemic corticosteroids, are excluded. Infants who are using topical steroids, topical antibiotic ointments and topical antifungal agents are not excluded. * Major congenital malformations, including congenital cleft palate, cytogenetic abnormalities, or serious chronic disorders * Previously received PIV3 vaccine * Previous serious vaccine-associated adverse event or anaphylactic reaction * Known hypersensitivity to any vaccine component * Lung or heart disease, including reactive airway disease. Infants with clinically insignificant cardiac abnormalities are not excluded. Infants or children who wheezed once or…