Trial to Evaluate the Immunogenicity of Dose Reduction Strategies of the MVA-BN Monkeypox Vaccine

JYNNEOS is FDA-approved and licensed as a smallpox and monkeypox vaccine in the United States. JYNNEOS is a live vaccine produced from the strain Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN), an attenuated, non-replicating orthopoxvirus. Each 0.5 mL dose is formulated to contain 0.5 x 10\^8 to 3.95 x 10\^8 infectious units of MVA-BN live virus in 10 mM Tris (tromethamine), 140 mM sodium chloride at pH 7.7. Subcutaneous is administered in the deltoid region, intradermal is administered in the volar aspect (inner side) of the forearm.