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

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

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.

Study Overview

• Status: Recruiting
• Conditions: Pneumococcal Infection
• Intervention / Treatment: Biological: V118C (Stage 1); Biological: V118C (Stage 2); Biological: PCV20 (Stage 1); Biological: PCV20 (Stage 2)

Detailed Description

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).

• Study Type: Interventional
• Enrollment (Estimated): 210
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Toll Free Number; Phone Number: 1-888-577-8839; Email: Trialsites@msd.com

Study Locations

• United States
  • California
    • Madera, California, United States, 93637
      • Recruiting
      • Madera Family Medical Group ( Site 1004)
      • Contact: Study Coordinator; Phone Number: 559-673-3000
  • Florida
    • Miami, Florida, United States, 33142
      • Recruiting
      • Acevedo Clinical Research Associates ( Site 1029)
      • Contact: Study Coordinator; Phone Number: 305-649-8871
    • Tampa, Florida, United States, 33606
      • Recruiting
      • University of South Florida-Department of Pediatrics ( Site 1002)
      • Contact: Study Coordinator; Phone Number: 813-821-8039
  • Kansas
    • Topeka, Kansas, United States, 66604
      • Recruiting
      • Cotton O'Neil Research Center ( Site 1039)
      • Contact: Study Coordinator; Phone Number: 785-354-6000
  • Kentucky
    • Louisville, Kentucky, United States, 40202
      • Recruiting
      • University of Louisville, Norton Children's Research Institute ( Site 1005)
      • Contact: Study Coordinator; Phone Number: 502-629-5820
  • Maryland
    • Columbia, Maryland, United States, 21045
      • Recruiting
      • The Pediatric Center ( Site 1025)
      • Contact: Study Coordinator; Phone Number: 443-721-7224
  • Missouri
    • St Louis, Missouri, United States, 63104
      • Recruiting
      • Saint Louis University Center for Vaccine Development ( Site 1031)
      • Contact: Study Coordinator; Phone Number: 314-977-6333
  • New York
    • East Syracuse, New York, United States, 13057
      • Recruiting
      • Child Health Care Associates ( Site 1035)
      • Contact: Study Coordinator; Phone Number: 315-652-8800
  • South Carolina
    • Greenville, South Carolina, United States, 29607
      • Recruiting
      • Tribe Clinical Research, LLC-Pediatrics ( Site 1008)
      • Contact: Study Coordinator; Phone Number: 864-334-0141
    • Spartanburg, South Carolina, United States, 29301
      • Recruiting
      • Tribe Clinical Research - Spartanburg ( Site 1001)
      • Contact: Study Coordinator; Phone Number: 864-334-0141
  • Texas
    • Carrollton, Texas, United States, 75006
      • Recruiting
      • Epic Medical Research - Carrollton ( Site 1038)
      • Contact: Study Coordinator; Phone Number: 972-777-6956
    • Garland, Texas, United States, 75043
      • Recruiting
      • Epic Medical Research- Garland ( Site 1017)
      • Contact: Study Coordinator; Phone Number: 972-777-6956
    • League City, Texas, United States, 77573
      • Recruiting
      • University of Texas Medical Branch ( Site 1020)
      • Contact: Study Coordinator; Phone Number: 832-340-2313
  • Virginia
    • Charlottesville, Virginia, United States, 22902
      • Recruiting
      • Pediatric Research of Charlottesville, LLC ( Site 1012)
      • Contact: Study Coordinator; Phone Number: 434-872-9384

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: Yes

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: V118C (Stage 1); Participants will receive a single 0.5 mL intramuscular (IM) injection of V118C administered at 12 to 15 months of age.	Biological: V118C (Stage 1); IM administration of V118C
Experimental: V118C (Stage 2); Participants will receive a single 0.5 mL IM injection of V118C administered at 2,4,6, and 12 months of age.	Biological: V118C (Stage 2); IM administration of V118C
Active Comparator: PCV20 (Stage 1); Participants will receive a single 0.5 mL IM injection of PCV20 administered at 12 to 15 months of age.	Biological: PCV20 (Stage 1); IM administration of PCV20
Active Comparator: PCV20 (Stage 2); Participants will receive a single 0.5 mL IM injection of PCV20 administered at 2,4,6, and 12 months of age.	Biological: PCV20 (Stage 2); IM administration of PCV20

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Stage 1: Percentage of Participants With Immediate Adverse Events (AEs) Following 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.	Up to approximately 30 minutes postvaccination
Stage 1: Percentage of Participants With Solicited Injection-Site Adverse Events (AEs)	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.	Up to approximately 7 days postvaccination
Stage 1: Percentage of Participants With Unsolicited Systemic or Injection-Site AEs	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.	Up to approximately 28 days postvaccination
Stage 1: Percentage of Participants With Serious Adverse Events (SAEs)	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.	Up to approximately 12 months postvaccination
Stage 1: Percentage of Participants With Medically Attended AEs (MAAEs)	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.	Up to approximately 12 months postvaccination
Stage 2: Percentage of Participants With Immediate AEs Following 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.	Up to approximately 30 minutes after each vaccination
Stage 2: Percentage of Participants With Solicited Injection-Site AEs	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.	Up to approximately 7 days after each vaccination
Stage 2: Percentage of Participants With Unsolicited Systemic or Injection-Site AEs	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.	Up to approximately 28 days after each vaccination
Stage 2: Percentage of Participants With SAEs	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.	Up to approximately 12 months postdose 4
Stage 2: Percentage of Participants With MAAEs	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.	Up to approximately 12 months postdose 4
Stage 1: Percentage of Participants With Solicited Systemic AEs	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.	Up to approximately 7 days postvaccination
Stage 2: Percentage of Participants With Solicited Systemic AEs	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.	Up to approximately 7 days after each vaccination

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Stage 1: Geometric Mean Concentrations (GMCs) of Serotype-Specific Immunoglobulin G (IgG)	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.	Up to approximately 30 days post vaccination
Stage 1: Ratio of GMCs of Serotype-Specific IgG of V118C to PCV20 [V118C/PCV20]	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.	Approximately Day 30 postvaccination
Stage 1: Geometric Mean Fold Rises (GMFRs) of Serotype-Specific Immunoglobulin G (IgG)	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.	Day 1 (Baseline) and approximately Day 30 postvaccination
Stage 1: Percentage of Participants With a ≥ 4-fold Rise for Serotype Specific IgG Concentrations	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.	Day 1 (Baseline) and approximately Day 30 postvaccination
Stage 2: Percentage of Participants With IgG ≥0.35 μg/mL (Response Rates) for Serotype Specific IgG Concentrations at 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.	Up to approximately 30 days postdose 3
Stage 2: Percentage of Participants With IgG ≥0.35 μg/mL (Response Rates) for Serotype Specific IgG Concentrations at 30 Days Predose 4	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.	Up to approximately 6 months post dose 3
Stage 2: Percentage of Participants With IgG ≥0.35 μg/mL (Response Rates) for Serotype Specific IgG Concentrations at 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.	Up to approximately 30 days postdose 4
Stage 2: Difference in the Response Rates [V118C minus PCV20] for Each Serotype at 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.	Up to approximately 30 days postdose 3
Stage 2: Difference in the Response Rates [V118C Minus PCV20] for Each Serotype at 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.	Up to approximately 30 days postdose 4
Stage 2: GMCs of Serotype-Specific IgG at 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.	Up to approximately 30 days postdose 3
Stage 2: GMCs of Serotype-Specific IgG at 30 Days Predose 4	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.	Up to approximately 6 months post dose 3
Stage 2: GMCs of Serotype-Specific IgG at 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.	Up to approximately 30 days postdose 4
Stage 2: Ratio of Serotype-Specific IgG GMCs of V118C to PCV20 [V118C/PCV20] at 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.	Up to approximately 30 days postdose 3
Stage 2: Ratio of Serotype-Specific IgG GMCs of V118C to PCV20 [V118C/PCV20] at 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.	Up to approximately 30 days postdose 4

Collaborators and Investigators

• Sponsor: Merck Sharp & Dohme LLC
• Investigators: Study Director: Medical Director, Merck Sharp & Dohme LLC

Publications and helpful links

Helpful Links

• Merck Clinical Trials Information

Study record dates

Study Major Dates

• Study Start (Actual): January 13, 2026
• Primary Completion (Estimated): October 24, 2028
• Study Completion (Estimated): May 25, 2029

Study Registration Dates

• First Submitted: December 10, 2025
• First Submitted That Met QC Criteria: December 10, 2025
• First Posted (Actual): December 23, 2025

Study Record Updates

• Last Update Posted (Actual): April 17, 2026
• Last Update Submitted That Met QC Criteria: April 15, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Infections; Gram-Positive Bacterial Infections; Bacterial Infections; Bacterial Infections and Mycoses; Streptococcal Infections; Pneumococcal Infections
• Other Study ID Numbers: V118C-002

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No