Medical Information Only. Consult your healthcare provider before considering clinical trial enrollment.
Diphtheria: later-stage trial registry
A small indexed set (16 trials) with no open enrollment listed right now.
Corpus placement: #1,060 of 28,707 conditions by registered trial count.
16 US clinical trials · none currently recruiting · #1,060 of 28,707 conditions by registered trial count
Diphtheria: 16 US clinical trials tracked, none currently recruiting.
Diphtheria is the subject of 16 registered US clinical trials on ClinicalTrials.gov, none currently recruiting. 12 are in Phase 3-4 (later-stage) and 3 in Phase 1-2 (earlier-stage). The most active sponsor is Sanofi Pasteur, a Sanofi Company, running 5 of these trials.
Enrollment posture brief
Registry condition diphtheria
OPEN 0 | RECR 0% | LATE 12 | EARLY 3 | RANK #1060 | SPON 5
Volume-matched condition peers
Nearest open-share peer: Accelerated Phase Chronic Myelogenous Leukemia (0% recruiting · 12 trials)
Diphtheria has no open enrollment in this registry pull (16 archived studies). Peers show how other volume-matched labels compare on open share. How peer matching works →
Key findings
What ClinicalTrials.gov does not surface for Diphtheria on its own pages , computed from the registry mirror as of 2026-08-08. Each line carries its own denominator so it can be quoted as it stands.
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Diphtheria is recruiting below its size-band peers.
0 of 16 indexed trials (0%) are open to enrollment, against a 46.5% average across 27,806 conditions with fewer than 20 trials. The peer set uses the same ClinicalTrials.gov-derived counts as this page.
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One sponsor concentrates Diphtheria research.
Sanofi Pasteur, a Sanofi Company accounts for 5 of 16 trials (31.3%). 5 distinct sponsors appear on at least one study for this condition label.
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Typical Diphtheria enrolment sits around 1,302 participants.
Median target enrolment is 1,302 among the 16 trials that report a genuine target (sentinel values excluded). 3 of those (18.8%) plan for fewer than 100 participants.
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Diphtheria research is mostly interventional.
15 interventional and 1 observational studies make up this index (93.8% interventional). Study type is sponsor-reported on ClinicalTrials.gov.
Indexed trials (enrollment closed)
16 total, page 1 of 1
Post-marketing Safety Study of GSK Biologicals' Boostrix® Vaccine
GlaxoSmithKline
NCT00297856
Immune Response and Safety Comparison of 3 Lots of GSK Biologicals' DTaP-IPV Candidate Vaccine to DTaP + IPV Vaccines
GlaxoSmithKline
NCT00148941
Study of DTap-IPV Compared to DAPTACEL® and IPOL® as the 5th Dose in Children 4 to 6 Years of Age
Sanofi Pasteur, a Sanofi Company
NCT01346293
Study of the Safety, Immunogenicity and Lot Comparability of DAPTACEL When Administered With Other Recommended Vaccine
Sanofi
NCT00662870
Study of Menactra® in Healthy Subjects at 9 Months and Concomitantly With Pentacel® at 15 to 18 Months of Age
Sanofi Pasteur, a Sanofi Company
NCT01659996
US-licensed Combined Vaccine Against Tetanus & Diphtheria, Given With US-licensed Vaccine Against Meningococcal Disease
GlaxoSmithKline
NCT00282295
Evaluation of GlaxoSmithKline Biologicals' Boostrix® Vaccine in Comparison With Decavac™ Vaccine.
GlaxoSmithKline
NCT00835237
Study of Adacel® Vaccine Administered to Persons 10 Years of Age
Sanofi
NCT01311557
Study of DAPTACEL® Administered as a 5th Dose in 4 to 6-Year-Old Children Previously Immunized With PENTACEL™
Sanofi Pasteur, a Sanofi Company
NCT00802867
Post-licensure, Modified Double-blind, Multi-center Study Evaluating Safety and Immunogenicity of ADACEL® and BOOSTRIX®
Sanofi
NCT00319553
Descriptive, Open-label, Multicenter Study of the Safety of Redosing With ADACEL® Vaccine
Sanofi Pasteur, a Sanofi Company
NCT00347958
Immunogenicity of Adacel® and BOOSTRIX® Vaccines in Adolescents
Sanofi Pasteur, a Sanofi Company
NCT01629589
Study on the Safety and Immunogenicity of Boostrix Vaccine in Pregnant Malian Women and Their Infants
National Institute of Allergy and Infectious Diseases (NIAID)
NCT03589768
Pertussis Vaccine in Healthy Pregnant Women
National Institute of Allergy and Infectious Diseases (NIAID)
NCT00707148
PFAS Exposure and Immune Response to Vaccination in Adults
Rutgers, The State University of New Jersey
NCT06588530
Pentavalent DTaP-Hep B-IPV
National Institute of Allergy and Infectious Diseases (NIAID)
NCT00133445
Phase Distribution
| Phase | Trial count |
|---|---|
| Phase 1 | 1 |
| Phase 2 | 2 |
| Phase 3 | 4 |
| Phase 4 | 8 |
Top Sponsors
Named interventions
Most-linked intervention names on Diphtheria records (sponsor-reported on ClinicalTrials.gov). Counts are trial links, not unique products.
US sites by state
Facility locations filed on Diphtheria trials. A trial with sites in several states counts in each.
Source: ClinicalTrials.gov, National Library of Medicine. Data is informational only.
Related
What to do with this Diphtheria page
16 registered trials, 0 currently recruiting, is a starting point for a conversation, not a diagnosis or a recommendation.
- No Diphtheria trials are currently recruiting in this registry; that can change as new trials post, or check the broader research index. Browse research indexes
- Sanofi Pasteur, a Sanofi Company sponsors the most Diphtheria trials on record, review their full trial history before evaluating a specific study. See Sanofi Pasteur, a Sanofi Company's trials
- Bring the specific trial ID (NCT number) to your own doctor before enrolling, this page is a directory, not medical guidance. Read the trial-finding guide
Trial and recruiting counts reflect ClinicalTrials.gov registry status as of the data vintage above; individual trial eligibility and enrollment status can change.
Every figure on PlainTrial is rendered directly from the ClinicalTrials.gov registry, no number is typed in by an editor. This Diphtheria condition card totals 16 registered trials; most-linked intervention Boostrix®; top US site state California. See our editorial standards & corrections policy, the methodology behind these numbers, the data changelog, or report a data error.