CI

At a glance

ClinicalIndex Comparison Record
Phase 3Completed· 1,600 enrolled
Drug / intervention
JYNNEOS (Liquid Formulation) +1 morebiological
Likely dose
JYNNEOS (Liquid Formulation) 0.5 mLfrom record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT02977715
NCT02977715Phase 3Completed

An Open-Label Prospective Cohort Study of JYNNEOS Smallpox Vaccine in Adult Healthcare Personnel at Risk for Mpox in the Democratic Republic of the Congo

Centers for Disease Control and Prevention·interventional·Posted Nov 30, 2016·Updated Apr 23, 2026

In Brief

A Phase 3 clinical trial evaluating JYNNEOS (Liquid Formulation) and JYNNEOS (Lyophilized Formulation) for Monkeypox Virus Infection. Completed, enrolled 1,600 participants across 1 site.

Detailed Summary

Mpox is a febrile rash illness caused by the monkeypox virus. Its natural occurrence in the DRC puts healthcare and frontline workers at high risk of acquiring monkeypox virus infections that can prevent them from performing work duties, compromise the overall healthcare delivery in an already fragile system, and can result in death (case fatality estimates are approximately 10%). This is an open-label prospective cohort study in up to 1,600 eligible healthcare workers at risk of mpox infection through their daily work. The study will document mpox exposure and infection in participants while concurrently evaluating the immunogenicity and safety of the vaccine, JYNNEOS (also known as MVA-BN, IMVAMUNE®, IMVANEX), in healthcare personnel in the DRC. Participation in the study is voluntary and open to male and female healthcare personnel ages 18 years and older in Tshuapa Province in The Democratic Republic of Congo who are at risk of monkeypox virus infection through their daily work or laboratory personnel performing diagnostic testing for monkeypox virus.

Study Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
CountriesDemocratic Republic of the Congo

Timeline

Phase 3CompletedFinished
2017201820192020202120222023202420252026
First PostedNov 30, 2016
Enrollment StartFeb 23, 2017
Primary CompletionOct 31, 2025
TodayJul 2, 2026
Enrollment to primary: 8.7 yearsPosted 9.6 years ago

Interventions

JYNNEOS (Liquid Formulation)biological

Two doses of attenuated live virus smallpox vaccine (JYNNEOS liquid formulation) administered on days 0 and 28 via subcutaneous injection (deltoid) (1 x 10\^8 Tissue Culture Infectious Dose 50 \[TCID50\] per 0.5 mL). A subset of participants will receive a booster dose.

JYNNEOS (Lyophilized Formulation)biological

Two doses of attenuated live virus smallpox vaccine (JYNNEOS lyophilized formulation) administered on days 0 and 28 via subcutaneous injection (deltoid) (1 x 10\^8 Tissue Culture Infectious Dose 50 \[TCID50\] per 0.5 mL). A subset of participants will receive a booster dose.