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JYNNEOS (Liquid Formulation)

Centers for Disease Control and Prevention · Phase 3 active Biologic

JYNNEOS is a live attenuated vaccinia virus vaccine that stimulates immune responses against orthopoxviruses, including monkeypox and smallpox.

JYNNEOS is a live attenuated vaccinia virus vaccine that stimulates immune responses against orthopoxviruses, including monkeypox and smallpox. Used for Prevention of monkeypox (mpox) in adults at risk of exposure, Prevention of smallpox in at-risk populations.

At a glance

Generic nameJYNNEOS (Liquid Formulation)
Also known asModified Vaccinia Ankara (MVA), MVA-BN, IMVAMUNE, IMVANEX
SponsorCenters for Disease Control and Prevention
Drug classLive attenuated viral vaccine
TargetOrthopoxvirus antigens (vaccinia virus envelope and core proteins)
ModalityBiologic
Therapeutic areaImmunology / Infectious Disease
PhasePhase 3

Mechanism of action

The vaccine contains a modified vaccinia Ankara (MVA) virus strain that replicates poorly in human cells but triggers both cellular and humoral immune responses. This primes the immune system to recognize and respond to orthopoxvirus antigens, providing protection against monkeypox and smallpox infection through antibody and T-cell mediated immunity.

Approved indications

Common side effects

Key clinical trials

Primary sources

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SourceUsed for
ClinicalTrials.govTrial enrolment, design, endpoints, results