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NCT Number: NCT06975878

Study of a 21-valent Pneumococcal Conjugate Vaccine in Healthy Infants From Approximately 2 Months of Age

This study is a Phase 3, randomized, modified double-blind study which aims to measure whether PCV21 vaccine (investigational pneumococcal conjugate vaccine) is safe and can help the body to develop germ-fighting agents called "antibodies" (immunogenicity) compared with 15vPCV (Vaxneuvance, licensed pneumococcal conjugate vaccine) when they are administered with routine pediatric vaccines in infants aged from approximately 2 months (42 to 112 days).

The study duration per participant will be up to approximately 20 months. The study vaccines (either PCV21 or 15-valent pneumococcal vaccines) will be administered at approximately 2, 4, and 11 to 15 months of age or at approximately 2, 3, 4, and 11 to 15 months of age (for preterm infants). Routine pediatric vaccines will be given at the same timepoints, as per local practice / recommendations.

• There will be 5 (for full-term infants) or 6 (for preterm infants) study visits:

* Full-term infants: Visit (V)01, V02 separated from V01 by 60 days, V03 separated from V02 by 30 days, V04 at 11 months of age until 15 months of age, V05 separated from V04 by 30 days. * Preterm infants: Visit (V)01, V02 separated from V01 by 30 days, V03 separated from V02 by 30 days, V04 separated from V03 by 30 days, V05 at 11 months of age until 15 months of age, V06 separated from V05 by 30 days.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

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Key information

Age range

42 day–112 day

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 3

Primary location

Investigational Site Number : 0560004, Alken, Belgium

Loading trial locations.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Aged 42 to 112 days on the day of inclusion
  • Participants who are healthy as determined by medical evaluation including medical history and physical examination
  • Born at full term of pregnancy (≥ 37 weeks) and with a birth weight ≥ 2.5 kg or born after a gestation period above 28 (> 28 weeks) through 36 weeks with a birth weight ≥ 1.5 kg, and in both cases medically stable as assessed by the investigator

Exclusion criteria

Participants are excluded from the study if any of the following criteria apply:

  • Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy; or long-term systemic corticosteroid therapy
  • History of microbiologically confirmed Streptococcus pneumoniae infection or disease
  • Any contraindication to the routine pediatric vaccines being administered in the study
  • History of seizure or significant stable or progressive neurological disorders such as infantile spasms, inflammatory nervous system diseases, encephalopathy, cerebral palsy
  • Known systemic hypersensitivity to any of the study interventions components, or history of a life-threatening reaction to the study interventions used in the study or to a product containing any of the same substances
  • Laboratory-confirmed or known thrombocytopenia, as reported by the parent/legally acceptable representative (LAR), contraindicating intramuscular (IM) injection
  • Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating IM injection
  • Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with study conduct or completion
  • Moderate or severe acute illness/infection (according to investigator judgment) or febrile illness (temperature ≥ 38.0°C [≥ 100.4°F]) on the day of study intervention administration. A prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided.
  • Receipt of any vaccine in the 4 weeks preceding the study intervention administration or planned receipt of any vaccine in the 4 weeks following the study intervention administration, except for oral rotavirus vaccine, which may be received anytime during the study including at study visits and for influenza vaccination or meningococcal b vaccine, which may be received at least 14 days before or 14 days after any study vaccination. This exception includes monovalent pandemic influenza vaccines and multivalent influenza vaccines, as applicable per local recommendations.
  • Previous vaccination against S. pneumoniae
  • Previous vaccination against the following antigens: diphtheria, tetanus, pertussis, Haemophilus influenzae type b, and poliovirus
  • Receipt of more than 1 dose of hepatitis B vaccine
  • Receipt of immune globulins, blood or blood-derived products since birth
  • Participation at the time of study enrollment (or in the 6 weeks preceding the first study intervention administration) or planned participation during the present study period in another clinical study investigating a vaccine, drug, medical device, or medical procedure

Note: The above information is not intended to contain all considerations relevant to a potential participation in a clinical trial.

Treatment and study plan

PCV21 vaccine

Biological

Pharmaceutical form:Suspension for injection-Route of administration:Intramuscular

Other names: 515

Vaxneuvance vaccine

Biological

Pharmaceutical form:Suspension for injection-Route of administration:Intramuscular

Other names: Vaxneuvance ™

Hexyon vaccine

Biological

Pharmaceutical form:Suspension for injection-Route of administration:Intramuscular

Other names: Hexyon®

M-M-RvaxPro vaccine

Biological

Pharmaceutical form:Powder and solvent for suspension for injection-Route of administration:Intramuscular or Subcutaneous

Other names: M-M-RVAX-PRO®

Varivax vaccine

Biological

Pharmaceutical form:Powder and solvent for suspension for injection-Route of administration:Intramuscular or Subcutaneous

Other names: Varivax®

Primary outcomes

  1. Seroresponse rate for PCV21 and 15vPCV serotypes

    Time frame: 30 days post-toddler dose

    Serotype specific IgG concentration ≥ 0.35 µg/mL

  2. IgG concentration for PCV21 and 15vPCV serotypes

    Time frame: 30 days post-toddler dose

    Serotype specific IgG Geometric Mean Concentration (GMC)

Secondary outcomes

  1. Anti- hepatitis B surface antigen (HBsAg) Ab

    Time frame: 30 days post-toddler dose

    % Antibody concentrations ≥ 10 milli international units per milliliter (mIU/mL)

  2. Anti- polyribosylribitol phosphate (PRP) Ab

    Time frame: 30 days post-toddler dose

    % Antibody concentrations ≥ 0.15 micrograms per milliliter (µg/mL)

  3. Anti-poliovirus types (1, 2, and 3) Ab

    Time frame: 30 days post-toddler dose

    % Antibody titers ≥ 1:8

  4. Anti-diphtheria Ab concentrations

    Time frame: 30 days post-toddler dose

    % Antibody concentration ≥ 0.1 IU/mL

  5. Anti-tetanus Ab concentrations

    Time frame: 30 days post-toddler dose

    % Antibody concentration ≥ 0.1 IU/mL

  6. Anti-pertussis Ab concentrations (Pertussis toxin (PT) and Filamentous Hemagglutinin (FHA))

    Time frame: 30 days post-toddler dose

    Antibody GMC

  7. Anti-measles Ab concentrations

    Time frame: 30 days post-toddler dose

    Antibody GMC

  8. Anti-mumps Ab concentrations

    Time frame: 30 days post-toddler dose

    Antibody GMC

  9. Anti-rubella Ab concentrations

    Time frame: 30 days post-toddler dose

    Antibody GMC

  10. Anti-varicella Ab concentrations

    Time frame: 30 days post-toddler dose

    Antibody GMC

  11. Anti HBsAg concentrations

    Time frame: 30 days post-primary series

    % Antibody concentrations ≥ 10 mIU/mL

  12. Anti-PRP Ab concentrations

    Time frame: 30 days post-primary series

    % Antibody concentrations ≥ 0.15 µg/mL

  13. Anti-poliovirus types (1, 2, and 3) Ab titers

    Time frame: 30 days post-primary series

    % Antibody titers ≥ 1:8

  14. Anti-diphtheria Ab concentrations

    Time frame: 30 days post-primary series

    % Antibody concentrations ≥ 0.1 IU/mL

  15. Anti-tetanus Ab concentrations

    Time frame: 30 days post-primary series

    % Antibody concentrations ≥ 0.1 IU/mL

  16. Anti-pertussis Ab concentrations (PT and FHA)

    Time frame: 30 days post-primary series

    Antibody GMC

  17. Serotype specific OPA titers for all serotypes included in PCV21

    Time frame: 30 days post-primary series

    Antibody Geometric mean titer (GMT)

  18. Serotype specific OPA titers for all serotypes included in PCV21

    Time frame: 30 days post-toddler dose

    Antibody GMT

  19. Presence of any immediate adverse events (AEs)

    Time frame: Within 30 minutes after each vaccine injection

    Number of participants experiencing immediate AEs

  20. Presence of solicited injection site and systemic reactions through 7 days after each vaccine injection

    Time frame: Through 7 days after each vaccine injection

    Number of participants experiencing solicited injection site and systemic reactions

  21. Presence of unsolicited (spontaneously reported) injection site reactions and unsolicited systemic AEs through 30 days after each vaccine injection

    Time frame: Through 30 days after each vaccine injection

    Number of participants experiencing unsolicited injection site reactions and unsolicited systemic AEs

  22. Presence of serious adverse events (SAEs) throughout the study (through 6 months post- last vaccine injection)

    Time frame: Throughout the study (through 6 months post-last vaccine injection), approximately 20 months

    Number of participants experiencing SAEs

  23. Presence adverse events of special interest (AESIs) throughout the study (through 6 months post- last vaccine injection)

    Time frame: Throughout the study (through 6 months post-last vaccine injection), approximately 20 months

    Number of participants experiencing AESIs

Sponsors and collaborators

Lead sponsor

Sanofi

Industry

Registry information

Official study title

A Phase 3, Randomized, Modified Double-blind, Active-controlled, Parallel-group, 2-arm Study to Investigate the Safety and Immunogenicity of a 21-valent Pneumococcal Conjugate Vaccine in Healthy Infants and Toddlers

Important dates

Study start
2025
Primary completion
2027
Study completion
2027
First posted
May 16, 2025
Registry last updated
Mar 2, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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