Evaluating a new combined vaccine for diphtheria, tetanus, and pertussis in young children

To Evaluate Safety and Preliminary Immunogenicity of the Diphtheria-Tetanus-acellular Pertussis Component Combined Vaccine in Children Aged 2 Months to 6 Years: A Randomized, Blinded, Active-controlled Phase I Clinical Trial

This study is testing a new combined vaccine for diphtheria, tetanus, and pertussis in young children to see if it is safe and helps their immune systems respond well.

Quick facts

• Phase: Phase 1
• Study type: Interventional
• Enrollment: 460 (estimated)
• Ages: 2 Months to 6 Years
• Sex: All
• Sponsor: Institute of Medical Biology, Chinese Academy of Medical Sciences (Academic / other)
• Drugs / interventions: prednisone
• Locations: 3 sites (Dazhou, Sichuan and 2 other locations)
• Trial ID: NCT06184542 on ClinicalTrials.gov

What this trial studies

This phase I clinical trial is designed to assess the safety and preliminary immunogenicity of the Diphtheria-Tetanus-acellular Pertussis Component Combined Vaccine (DTacP) in children aged 2 months to 6 years. The study involves a randomized, blinded, active-controlled approach with a total of 460 subjects, who will receive either the DTacP vaccine or other control vaccines. Safety will be monitored through various adverse event assessments, while immunogenicity will be evaluated by measuring antibody responses after vaccination. The trial is structured in two stages, starting with older children and progressing to younger infants based on safety data.

Who should consider this trial

Good fit: Ideal candidates for this study are children aged 2 months to 6 years who meet specific vaccination history criteria.

Not a fit: Patients who have already received certain vaccines or are outside the specified age range may not benefit from this study.

Why it matters

Potential benefit: If successful, this vaccine could enhance protection against diphtheria, tetanus, and pertussis in young children.

How similar studies have performed: Other studies have shown success with similar vaccine approaches, indicating potential for this trial's success.

Eligibility criteria

Inclusion Criteria:

* Age Requirement: children aged 6 years, toddlers aged 18-24 months, and infants aged 2-3 months at the time of enrollment
* Previous Vaccination Requirements: (a) Children (aged 6 years) enrolled in the study should have received four doses of the Diphtheria, Tetanus, and Pertussis combined vaccine, and not yet received the Diphtheria, Tetanus combined vaccine; (b) Toddlers (aged 18-24 months) enrolled in the study should have received three doses of Diphtheria, Tetanus, and Pertussis combined vaccine as well as three doses of the Polio vaccine, and not yet received the booster dose of Diphtheria, Tetanus, and Pertussis combined vaccine and the Polio vaccine; (c) Infants (aged 3 months) enrolled in the study should not have received diphtheria-tetanus-pertussis-containing vaccine, polio-containing vaccine, 13-valent pneumococcal polysaccharide conjugate vaccine, Haemophilus influenzae type b conjugate vaccine, or meningococcal group A and C polysaccharide conjugate vaccine; (d) Infants (aged 2 months) enrolled in the study should not received diphtheria-tetanus-pertussis-containing vaccine, polio-containing vaccine, 13-valent pneumococcal polysaccharide conjugate vaccine, or Haemophilus influenzae type b conjugate vaccine.
* Provision of Legal Identification: Volunteers and their legal guardians or appointed representatives must provide valid legal identification documents.
* Informed Consent: Legal guardians or appointed representatives of volunteers must have the capacity to understand the informed consent document and the research process, voluntarily participate, sign the informed consent form, and be able to comply with the requirements in the study as well as complete relevant visits on time.
* Birth Outcome Condition: Toddlers (aged 18-24 months) and Infants (aged 2-3 months) should be born at full term (37-42 weeks of gestation) with birth weight ≥2500g.
* Temperature Requirement: Axillary body temperature is no more than 37.3°C.

Exclusion Criteria:

Subjects meeting any of the following exclusion criteria will be not eligible for enrollment.

* Previous Diagnosis: Subjects diagnosed with pertussis, tetanus, or diphtheria disease.
* Special Conditions for Toddlers (aged 18-24 months) and Infants (aged 2-3 months): Subjects have been with abnormal labor (dystocia, instrumental delivery) or a history of asphyxia, nervous system damage, or clinically confirmed pathological jaundice.
* Allergic History: Subjects have a history of allergies to any component of the vaccine (such as aluminum hydroxide), or previous allergy or suspected allergy to any vaccine, or other serious adverse reactions, such as anaphylactic shock, laryngeal edema, anaphylactic purpura, thrombocytopenic purpura, local anaphylactic necrosis reaction, dyspnea, angioedema, systemic rash and/or urticaria.
* Vaccination History: Subjects received any inactivated vaccines or subunit vaccines within 7 days before vaccination (except COVID-19 vaccines) with the investigational vaccine, or any other live attenuated vaccines or COVID-19 vaccines within 14 days before vaccination
* Acute Illness: Subjects have acute illness (e.g., fever) or acute exacerbation of a chronic illness within 3 days before receipt of the first dose of the investigational vaccine
* Neurological and Mental Health: Subjects have a history or family history of seizures, epilepsy, and other encephalopathy and psychiatric disorders.
* Health Condition: Subjects have a major congenital malformation, developmental disability, or congenital disease (e.g., Down syndrome, sickle cell anemia, congenital neurological disorders), or other clinically diagnosed serious chronic disease, including but not limited to, serious diseases of the nervous system, cardiovascular system, blood and lymphatic system, immune system, kidney, liver, gastrointestinal tract, respiratory system, metabolic system, skeletal system and other system and malignant tumor history.
* Blood Disease: Subjects have genetic bleeding tendency or coagulopathy, or a history of bleeding disorders.
* Infectious Disease: Subjects diagnosed with infectious diseases that may interfere with the study, such as tuberculosis, viral hepatitis, human immunodeficiency virus (HIV) infection, etc.
* Special Condition: Subjects who cannot tolerate venipuncture or have a history of needle and blood sickness.
* Organ Removal History: Subjects with surgical removal of the spleen or other vital organs for any reason.
* Blood Condition: Subjects with blood loss (≥400 ml) and receipt of blood or blood products in the 3 months before receipt of the first dose of the investigational vaccine
* Immune Therapy: Subjects received treatment with an immunosuppressive agent, such as long-term systemic glucocorticoid therapy (treatment with systemic glucocorticoids, such as prednisone or a similar agent, for more than 2 consecutive weeks within 6 months before receipt of the first dose of an investigational vaccine), except topical agents (such as ointments, eye drops, inhalers, or nasal sprays) that do not exceed the recommended dose in the label or have any signs of systemic exposure
* Participation in Other Clinical Studies: Subjects use any investigational or unregistered product (drug, biologic product, or device) within 3 months before receipt of the first dose of the investigational vaccine, plan to use such product during the duration of this study, or were enrolled in another clinical trial before enrollment in this study.
* Physical Examination: (a) Subjects with abnormal vital signs with clinical significance; (b) Subjects abnormal blood routine, blood biochemistry, and urine routine test indicators with clinical significance
* Investigator's Discretion: The final exclusion criterion is the investigator's discretion to determine whether a subject is suitable for participation in the study.

Contraindications of the second and third doses of the vaccine:

Subjects meeting any of the following contraindications will be not eligible for the following doses.

* Serious Adverse Events: Subjects experienced serious adverse events related to vaccination after the previous dose.
* Vaccination with other vaccines during the study: (a) Subjects received other diphtheria, Tetanus, and acellular pertussis combined vaccines except for the investigational vaccine after the previous dose during the study period; (b) Infants (C3 subgroup and D3 subgroup) received other polio vaccines after the previous dose during the study period.
* Ineligibility: Subjects cannot be eligible or meet exclusion criteria after the previous dose of the investigational vaccine, and the qualification should be determined by the investigator.
* Investigator's Discretion: Subjects determined by the investigator as unsuitable for the following study period.

Where this trial is running

Dazhou, Sichuan and 2 other locations

• Dazhu Center for Disease Prevention and Control — Dazhou, Sichuan, China (Recruiting)
• Cuiping Center for Disease Prevention and Control — Yibin, Sichuan, China (Not_yet_recruiting)
• Xingwen Center for Disease Prevention and Control — Yibin, Sichuan, China (Not_yet_recruiting)

Study contacts

• Study coordinator: Jingsi Yang

Conditions Diphtheria; Tetanus; Pertussis