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Home › Conditions › Smallpox

Smallpox

Part of Orthopoxvirus Infection

1 published article · Updated continuously

Clinical Trial Landscape

Clinical Trials for Smallpox

20 trials tracked for Smallpox: 7 in phase 3 or 4 and 3 with published results. The most-cited published study has 418 citations.

20Trials tracked
7Phase 3 & 4
0Recruiting
3With published results
Phase distribution
Phase 4 2 Phase 3 5 Phase 2 12 Phase 1 1
  1. Phase 3 A Trial to Assess the Safety, Tolerability, and Pharmacokinetics of the Anti-Orthopoxvirus Compound Tecovirimat Completed · 418 cited
  2. Phase 3 A Trial to Evaluate Immunogenicity and Safety of Three Consecutive Production Lots of IMVAMUNE® (MVA-BN®) Smallpox Vaccine in Healthy, Vaccinia-naïve Subjects Completed · 66 cited
  3. Phase 3 Freeze-Dried MVA-BN® Lot Consistency Smallpox Trial Completed · 18 cited
  4. Phase 4 Safety, Tolerability and PK of TPOXX in Adults Weighing More Than 120 KG Completed
  5. Phase 4 Drug-drug Interaction Study of TPOXX When Co-administered With Phosphate Binders Completed
  6. Phase 3 Safety, Tolerability and Pharmacokinetics of TPOXX When Administered Orally for 28 Days Completed
Show 14 more trials
  1. Phase 3 Safety and Efficacy of CJ-50300 in Healthy Volunteers Completed
  2. Phase 2 A Phase II Trial to Compare a Liquid-frozen and a Freeze-dried Formulation of IMVAMUNE (MVA-BN®) Smallpox Vaccine in Vaccinia-naïve Healthy Subjects Completed
  3. Phase 2 Dose Study of ACAM2000 Smallpox Vaccine in Previously Vaccinated Adults Completed
  4. Phase 2 A Randomized, Double-blind, Placebo-controlled Study on Immunogenicity and Safety of MVA-BN (IMVAMUNE™) Smallpox Vaccine in Healthy Subjects Completed
  5. Phase 2 ACAM 3000 MVA at Harvard Medical School Completed
  6. Phase 2 Lyophilized IMVAMUNE® (1x10^8 TCID50) Versus Liquid IMVAMUNE® (1x10^8 TCID50) Administered Subcutaneously and a Lower Dose Liquid IMVAMUNE® (2x10^7 TCID50) Administered Intradermally Completed
  7. Phase 2 Phase II Trial to Assess Safety and Immunogenicity of IMVAMUNE® Completed
  8. Phase 2 An Open-Label Phase II Study to Evaluate Immunogenicity and Safety of a Single IMVAMUNE Booster Vaccination Two Years After the Last IMVAMUNE Vaccination in Former POX-MVA-005 Vaccinees Completed
  9. Phase 2 Effect of Dose, Safety, Tolerability of a New Smallpox Vaccine in Adults Without Previous Smallpox Vaccination Completed
  10. Phase 2 High Dose IMVAMUNE® in Vaccinia-Naive Individuals Completed
  11. Phase 2 A Study to Evaluate Safety and Immunogenicity of One and Two Doses of IMVAMUNE® Smallpox Vaccine in 56-80 Year Old Vaccinia-experienced Subjects Completed
  12. Phase 2 Randomized, Open-label Phase II Trial to Assess the Safety and Immunogenicity of MVA-BN Smallpox Vaccine in Immunocompromised Subjects With HIV Infection Completed
  13. Phase 2 MVA Post-Event: Administration Timing and Boost Study Completed
  14. Phase 1 Phase I Trial of an Investigational Small Pox Medication Completed

Showing the 20 most-cited and recently-updated of 20 trials. Browse the full registry →

Trial data sourced from ClinicalTrials.gov. Counts describe the research landscape and are not a treatment recommendation. Informational only — not medical advice.

What the trials found For clinicians

Smallpox: what the trials found

Several interventions have been evaluated for smallpox management, including the antiviral tecovirimat [1, 3], Tpoxx [2, 6], and various vaccine formulations. Tecovirimat was assessed in Phase 4 1 and Phase 3 3 trials. Tpoxx was evaluated in Phase 4 studies, where monitoring of hemoglobin concentration, serum chemistry, and urinalysis pH were recorded [2, 6].

Vaccination strategies include IMVAMUNE® (MVA Smallpox Vaccine), which has been studied extensively across multiple phases [10, 12, 13, 14, 19]. Clinical data for IMVAMUNE® indicate high booster rates by ELISA (up to 100%) and PRNT (ranging from 85.7% to 100%) 13. Safety profiles for IMVAMUNE® show low incidences of Grade 3 or 4 laboratory toxicities 10 and limited instances of related Grade 3 or higher adverse events in various cohorts [12, 14].

Other vaccine candidates include FD MVA-BN 5, which showed very low rates of Grade 3 or 4 unsolicited adverse events 5, and the CJ-50300 smallpox vaccine 7. Research into administration methods for MVA Smallpox Vaccine indicates that local injection site reactions were not significantly different between Stratis™ delivery and traditional syringe/needle administration (p=0.4782) 16.

Recent results — preliminary, needs further review

  • A Phase 2 trial evaluated a live vaccinia virus vaccine 8.

For the clinician treating this condition

  • Tecovirimat and Tpoxx are established interventions for smallpox, with clinical data available regarding their safety and physiological monitoring [1, 2, 3, 6].
  • IMVAMUNE® (MVA Smallpox Vaccine) demonstrates high seroconversion and booster rates via both ELISA and PRNT assays [12, 13].
  • Safety data for MVA-based vaccines (including FD MVA-BN) indicate a low frequency of severe adverse events or laboratory toxicities [5, 10].

AI synthesis of 8 cited trials, updated Jun 27, 2026. Informational only — not medical advice; trial data sourced from ClinicalTrials.gov. How we use AI.

HCP Mode — summaries include clinical detail, trial data, and statistical outcomes.
Patient Mode — summaries use plain language, avoiding clinical jargon.
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