🏛️ Verified NIH Record • Updated 2026-03-27
Study to Assess the Safety and Immunogenicity of TPOXX® When Administered Orally for 28 Days With JYNNEOS (NCT04957485)
A Phase 1, Open-Label (JYNNEOS®), Double-Blind (TPOXX® And Placebo), Multicenter, Randomized, Placebo-Controlled, Drug-Vaccine Interaction Study To Evaluate the Impact of TPOXX on JYNNEOS Immunogenicity
🔵 Active, Not Recruiting Phase2 💊 Investigational Drug / Biologic Sponsor: SIGA Technologies
🩺 Plain-English Summary (8th-Grade Level)
This study is designed to evaluate the immunogenicity profile of JYNNEOS® when 2 doses are administered subcutaneously (SC) 4 weeks apart; and potential immunological interference while concomitantly administering TPOXX or placebo orally twice daily (BID) for 28 days.
Who can join: Review the eligibility criteria below.
Location: Meridian Clinical Research — Omaha, Nebraska
Age range: 18 Years to 42 Years
🧪 Interventions in This Study
📋 "Do I Qualify?" — 1-Minute Self Screener
Instant ChecklistFull eligibility criteria are available on the official NIH protocol. View the criteria ↗
📍 All Participating Trial Locations (2 Sites)
- Meridian Clinical Research — Omaha, Nebraska
- Aventiv Research Inc — Columbus, Ohio
💰 Cost, Insurance & Patient Rights
- 100% Free Items: The investigational treatment and protocol-required procedures are supplied at zero cost by the sponsor.
- Routine Patient Care: Under federal law (ACA § 2709) and many state statutes, routine care costs are covered during participation.
- Voluntary Participation: You may withdraw at any time without affecting your standard medical care.
Explore by condition: All Smallpox clinical trials
💡 How to Participate
- Check the checklist above to see if you may qualify.
- Review the official NIH record below to find the coordinating site.
- Ask about the visit schedule, what is covered at no cost, and any travel support.
- Confirm with your own doctor before making a decision.