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NCT Number: NCT07300267

A Clinical Study of Novel Pneumococcal Vaccine V118C in Children (V118C-002)

Researchers are looking for new vaccines to prevent pneumococcal disease, which is any infection in the lungs or other parts of the body that is caused by a type of bacteria called Streptococcus pneumoniae. V118C is a new vaccine designed to help prevent disease from Streptococcus pneumoniae bacteria.

This study will look at V118C in toddlers and infants. The goal of the study is to learn how safe V118C is for children and how well they tolerate it.

Recruiting

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Key information

Conditions

Pneumococcal Infection Bacterial Infections Bacterial Infections and Mycoses Gram-Positive Bacterial Infections Infections Pneumococcal Infections Streptococcal Infections

Age range

2 month–15 month

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1

Primary location

Madera Family Medical Group ( Site 1004), Madera, California, United States

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About this study

Stage 1 of the study will be conducted in toddlers enrolled at 12 through 15 months of age who previously completed a primary 3-dose infant series with a licensed pneumococcal conjugate vaccine (PCV). Stage 2 will be conducted in infants enrolled at approximately 2 months of age, who will receive the 3+1 schedule (3 infant doses followed by a toddler dose).

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

The main inclusion criteria include but are not limited to the following:

Stage 1:

  • Is previously vaccinated with 3 routine infant doses of Pneumococcal 20-valent conjugate vaccine (PCV20)
  • Is 12 through 15 months of age

Stage 2:

  • Is approximately 2 months of age

Both Stages:

  • Was born at full term (gestational age greater than or equal to 37 weeks)

Exclusion criteria

The main exclusion criteria include but are not limited to the following:

Stage 1:

  • Has received a PCV dose at 10 months of age and older

Stage 2:

  • Has received prior administration of any pneumococcal vaccine

Both stages:

  • Has a history of invasive pneumococcal disease (IPD)
  • Has a known hypersensitivity to any component of V118C or PCV20 including diphtheria toxoid

Treatment and study plan

V118C (Stage 1)

Biological

IM administration of V118C

V118C (Stage 2)

Biological

IM administration of V118C

PCV20 (Stage 1)

Biological

IM administration of PCV20

PCV20 (Stage 2)

Biological

IM administration of PCV20

Primary outcomes

  1. Stage 1: Percentage of Participants With Immediate Adverse Events (AEs) Following Vaccination

    Time frame: Up to approximately 30 minutes postvaccination

    An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Percentage of participants with immediate AEs following vaccination will be reported.

  2. Stage 1: Percentage of Participants With Solicited Injection-Site Adverse Events (AEs)

    Time frame: Up to approximately 7 days postvaccination

    An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. A solicited AE is a predefined event that participants legally acceptable representative (LAR) are specifically asked about and record on their electronic vaccine report card (eVRC). Solicited injection-site AEs include redness, swelling, pain or tenderness and hard lump. Percentage of participants with solicited injection-site AEs will be reported.

  3. Stage 1: Percentage of Participants With Solicited Systemic AEs

    Time frame: Up to approximately 7 days postvaccination

    An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. A solicited AE is a predefined event that participants LAR are specifically asked about and record on their eVRC. Solicited systemic AEs include irritability, drowsiness, appetite lost, hives or welts, and fever. Percentage of participants with solicited systemic AEs will be reported.

  4. Stage 1: Percentage of Participants With Unsolicited Systemic or Injection-Site AEs

    Time frame: Up to approximately 28 days postvaccination

    An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An unsolicited AE is an event that is not solicited using a eVRC and that is communicated by a participant. Percentage of participants with unsolicited Systemic or Injection-Site AEs will be reported.

  5. Stage 1: Percentage of Participants With Serious Adverse Events (SAEs)

    Time frame: Up to approximately 12 months postvaccination

    A serious adverse event (SAE) is an AE that is life-threatening, requires or prolongs an existing hospitalization, results in persistent or significant disability or incapacity, is a congenital anomaly or birth defect, or is another important medical event deemed such by medical or scientific judgment. Percentage of participants with one or more SAEs will be reported.

  6. Stage 1: Percentage of Participants With Medically Attended AEs (MAAEs)

    Time frame: Up to approximately 12 months postvaccination

    A MAAE is defined as an adverse event in which medical attention is received during an unscheduled, non-routine outpatient visit, such as an emergency department visit, office visit, or an urgent care visit with any medical personnel for any reason. Percentage of participants with MAAEs will be reported.

  7. Stage 2: Percentage of Participants With Immediate AEs Following Vaccination

    Time frame: Up to approximately 30 minutes after each vaccination

    An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Percentage of participants with immediate AEs following vaccination will be reported.

  8. Stage 2: Percentage of Participants With Solicited Injection-Site AEs

    Time frame: Up to approximately 7 days after each vaccination

    An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. A solicited AE is a predefined event that participants LAR are specifically asked about and record on their eVRC. Solicited injection-site AEs include redness, swelling, pain or tenderness and hard lump. Percentage of participants with solicited injection-site AEs will be reported.

  9. Stage 2: Percentage of Participants With Solicited Systemic AEs

    Time frame: Up to approximately 7 days after each vaccination

    An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. A solicited AE is a predefined event that participants LAR are specifically asked about and record on their eVRC. Solicited systemic AEs include irritability, drowsiness, appetite lost, hives or welts, and fever. Percentage of participants with solicited systemic AEs will be recorded.

  10. Stage 2: Percentage of Participants With Unsolicited Systemic or Injection-Site AEs

    Time frame: Up to approximately 28 days after each vaccination

    An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An unsolicited AE is an event that is not solicited using a eVRC and that is communicated by a participant. Percentage of participants with unsolicited Systemic or Injection-Site AEs will be reported.

  11. Stage 2: Percentage of Participants With SAEs

    Time frame: Up to approximately 12 months postdose 4

    A SAE is an AE that is life-threatening, requires or prolongs an existing hospitalization, results in persistent or significant disability or incapacity, is a congenital anomaly or birth defect, or is another important medical event deemed such by medical or scientific judgment. Percentage of participants with one or more SAEs will be reported.

  12. Stage 2: Percentage of Participants With MAAEs

    Time frame: Up to approximately 12 months postdose 4

    A MAAE is defined as an adverse event in which medical attention is received during an unscheduled, non-routine outpatient visit, such as an emergency department visit, office visit, or an urgent care visit with any medical personnel for any reason. Percentage of participants with MAAEs will be reported.

Secondary outcomes

  1. Stage 1: Geometric Mean Concentrations (GMCs) of Serotype-Specific Immunoglobulin G (IgG)

    Time frame: Up to approximately 30 days post vaccination

    The GMCs for serotype-specific IgG antibodies will be determined using pneumococcal electrochemiluminescence (Pn ECL) assay. GMCs of Serotype-specific IgG at 30 days postvaccination with V118C and PCV20 will be reported.

  2. Stage 1: Ratio of GMCs of Serotype-Specific IgG of V118C to PCV20 [V118C/PCV20]

    Time frame: Approximately Day 30 postvaccination

    The GMCs for serotype-specific IgG antibodies will be determined using pneumococcal electrochemiluminescence (Pn ECL) assay. Ratio of GMCs of serotype-specific IgG of V118C to PCV20 will be reported.

  3. Stage 1: Geometric Mean Fold Rises (GMFRs) of Serotype-Specific Immunoglobulin G (IgG)

    Time frame: Day 1 (Baseline) and approximately Day 30 postvaccination

    Geometric mean fold rise (GMFR) is defined as the geometric mean of the ratio of concentration at Day 30 after vaccination divided by concentration at baseline. GMFRs of serotype-specific IgG from baseline (Day 1) to Day 30 with V118C and PCV20 for IgG responses will be reported.

  4. Stage 1: Percentage of Participants With a ≥ 4-fold Rise for Serotype Specific IgG Concentrations

    Time frame: Day 1 (Baseline) and approximately Day 30 postvaccination

    The percentage of participants with ≥4-fold rise from baseline (Day 1) to Day 30 with V118C and PCV20 for IgG responses will be reported.

  5. Stage 2: Percentage of Participants With IgG ≥0.35 μg/mL (Response Rates) for Serotype Specific IgG Concentrations at 30 Days Postdose 3

    Time frame: Up to approximately 30 days postdose 3

    Percentage of participants with IgG ≥0.35 μg/mL (response rates) for each serotype at 30 days postdose 3 (PD3) with V118C and PCV20 will be reported will be reported.

  6. Stage 2: Percentage of Participants With IgG ≥0.35 μg/mL (Response Rates) for Serotype Specific IgG Concentrations at 30 Days Predose 4

    Time frame: Up to approximately 6 months post dose 3

    Percentage of participants with IgG ≥0.35 μg/mL (response rates) for each serotype at predose 4 (PD4) with V118C and PCV20 will be reported.

  7. Stage 2: Percentage of Participants With IgG ≥0.35 μg/mL (Response Rates) for Serotype Specific IgG Concentrations at 30 Days Postdose 4

    Time frame: Up to approximately 30 days postdose 4

    Percentage of participants with IgG ≥0.35 μg/mL (response rates) for each serotype at 30 days postdose 4 with V118C and PCV20 will be reported.

  8. Stage 2: Difference in the Response Rates [V118C minus PCV20] for Each Serotype at 30 Days Postdose 3

    Time frame: Up to approximately 30 days postdose 3

    Difference in the response rates [V118C minus PCV20] for each serotype at 30 days postdose 3 with V118C and PCV20 will be reported.

  9. Stage 2: Difference in the Response Rates [V118C Minus PCV20] for Each Serotype at 30 Days Postdose 4

    Time frame: Up to approximately 30 days postdose 4

    Difference in the response rates [V118C minus PCV20] for each serotype at 30 days postdose 4 with V118C and PCV20 will be reported.

  10. Stage 2: GMCs of Serotype-Specific IgG at 30 Days Postdose 3

    Time frame: Up to approximately 30 days postdose 3

    The GMCs for serotype-specific IgG antibodies will be determined using pneumococcal electrochemiluminescence (Pn ECL) assay. GMCs of serotype-specific IgG at 30 days postdose 3 with V118C and PCV20 will be reported.

  11. Stage 2: GMCs of Serotype-Specific IgG at 30 Days Predose 4

    Time frame: Up to approximately 6 months post dose 3

    The GMCs for serotype-specific IgG antibodies will be determined using pneumococcal electrochemiluminescence (Pn ECL) assay. Serotype-specific IgG GMCs at 30 days predose 4 with V118C and PCV20 will be reported.

  12. Stage 2: GMCs of Serotype-Specific IgG at 30 Days Postdose 4

    Time frame: Up to approximately 30 days postdose 4

    The GMCs for serotype-specific IgG antibodies will be determined using pneumococcal electrochemiluminescence (Pn ECL) assay. Serotype-specific IgG GMCs at 30 days postdose 4 with V118C and PCV20 will be reported.

  13. Stage 2: Ratio of Serotype-Specific IgG GMCs of V118C to PCV20 [V118C/PCV20] at 30 Days Postdose 3

    Time frame: Up to approximately 30 days postdose 3

    The GMCs for serotype-specific IgG antibodies will be determined using pneumococcal electrochemiluminescence (Pn ECL) assay. Ratio of serotype-specific IgG GMCs of V118C to PCV20 [V118C/PCV20] at 30 days postdose 3 will be reported.

  14. Stage 2: Ratio of Serotype-Specific IgG GMCs of V118C to PCV20 [V118C/PCV20] at 30 Days Postdose 4

    Time frame: Up to approximately 30 days postdose 4

    The GMCs for serotype-specific IgG antibodies will be determined using pneumococcal electrochemiluminescence (Pn ECL) assay. Ratio of serotype-specific IgG GMCs of V118C to PCV20 [V118C/PCV20] at 30 days postdose 4 will be reported.

Study contacts

Contact information is provided by the study sponsor or research team.

Toll Free Number

CONTACT

[email protected]

1-888-577-8839

Sponsors and collaborators

Lead sponsor

Merck Sharp & Dohme LLC

Industry

Registry information

Official study title

A Phase 1, Randomized, Double-Blind, Active Comparator Controlled Study to Evaluate the Safety, Tolerability, and Immunogenicity of a Novel Pneumococcal Vaccine in Children

Important dates

Study start
2026
Primary completion
2028
Study completion
2029
First posted
Dec 23, 2025
Registry last updated
Apr 17, 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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