A Phase 1 Study to Evaluate Safety & Immunogenicity of RVSV-Nipah Virus Vaccine Candidate PHV02 in Healthy Adult Subjects

Inclusion Criteria: * For Booster cohort only: received PHV02 (or placebo) * Healthy, adult, male or non-pregnant, non-lactating females * Given written informed consent * No clinically significant health problems * Agree to avoid conception through Day 29 * Agree to minimize blood and body fluid exposures to others after vaccination through Day 29 * Agree to avoid exposure to immunocompromised persons after vaccination through Day 29 * Agree to avoid employment in industry involved with livestock after vaccination through Day 29 Exclusion Criteria: * Signs or symptoms of acute COVID-19 within 1 week before vaccination. * Prior infection with Nipah virus or suspected Henipavirus * Healthcare worker with direct physical contact with patients * Childcare worker in direct contact with children 5 years old or younger * Household contact who is immunodeficient, or on immunosuppressive medication * Hands-on food preparation job * Primary care or treatment of cattle, horses, llamas or swine * Hepatitis B, hepatitis C, HIV-1, HIV-2, diabetes, atopic dermatitis (eczema), chronic inflammatory disease, autoimmune or autoinflammatory disorder, malignancy, chronic or active neurologic disorder, ; * History of severe reactions to any vaccine or history of severe allergies * Receipt of another investigational vaccine within 30 days or a licensed vaccine within 14 days (live vaccine within 30 days) * Known allergy to components of PHV02 * Injection sites obscured by tattoos or physical condition * Significant psychiatric or medical condition or laboratory abnormality on screening * History of Guillain Barre Syndrome or any chronic or acute neurological disorder * Alcohol or illicit drug abuse within past 5 years * Pregnant or lactating female * Administration of blood or IgG within 120 days preceding study * History of blood donation within 60 days of study * Unwilling to undergo diagnostic evaluation of rash (skin biopsy, if indicated) or joint symptoms (athrocentesis if indicated by joint effusion), in both cases if acceptable to subject * History of chronic autoimmune/autoinflammatory disease * Elective surgery planned during the study period * Subjects who have not adhered to and do not agree to adhere to local and institutional guidelines for COVID-19 prevention or testing * Any subject from the Pioneer/Full cohort who experienced a hypersensitivity reaction to study vaccine or a single clinically significant Grade 3 adverse event or serious adverse event, unless deemed unrelated to vaccination, will be followed for safety and immunogenicity, but will not be eligible to enter the Booster Cohort