Safety of a Live Attenuated Human Parainfluenza Virus Type 2 (HPIV2) Vaccine for Adults, Children, and Infants

Inclusion Criteria for Adults: * 18 to 49 years old * In good health, measured by lack of significant medical illness, physical examination findings, or significant laboratory abnormalities of urinalysis, complete blood count (CBC), ALT, or creatinine, as determined by the investigator Exclusion Criteria for Adults: * Pregnancy * Breastfeeding * Females of childbearing potential who are unwilling to practice effective birth control * Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, or renal disease by history, physical examination, or laboratory studies, including urinalysis * Behavioral, cognitive, or psychiatric disease that, in the opinion of the investigator, affects the ability of the participant to understand and cooperate with the study protocol * Other condition that, in the opinion of the investigator, would jeopardize the safety or rights of a participant participating in the study or would render the participant unable to comply with the protocol * Has had medical, occupational, or family problems as a result of alcohol or illicit drug use during the past 12 months * History of a severe allergic reaction or anaphylaxis * History of splenectomy * Diagnosis of asthma within the past 2 years * Positive enzyme-linked immunoassay (ELISA) and confirmatory Western blot tests for HIV-1 * Positive ELISA and confirmatory immunoblot tests for hepatitis C virus (HCV) * Positive ELISA hepatitis B surface antigen (HBsAg) t…