A Study to Evaluate V181 Dengue Vaccine in Healthy Participants 2 to 17 Years of Age (V181-005/MOBILIZE-1)

Phase 3

Recruiting

• Conditions: Healthy
• Interventions: Biological: V181; Biological: Placebo

• Registration Number: NCT07013487
• Lead Sponsor: Merck Sharp & Dohme LLC

Brief Summary

The purpose of this study is to demonstrate that V181 is safe and well tolerated, elicits an immune response, and reduces the frequency of virologically confirmed dengue (VCD) of any severity, due to any of the 4 dengue serotypes, regardless of dengue serostatus at baseline in children 2 to 17 years of age.

Detailed Description

The Reactogenicity and Immunogenicity Subset consists of approximately 3600 participants who will be followed for immunogenicity and safety through 28 days postvaccination. The Long-term Immunogenicity Subset consists of approximately 620 participants randomly selected from the Reactogenicity and Immunogenicity Subset and will evaluate virus reduction neutralization test (VRNT) at designated timepoints up to 5 years postvaccination.

Study Timeline

• Status Verified: 2025-06
• Study First Submitted: 2025-06-02
• Study First Submitted QC: 2025-06-02
• Study First Posted: 2025-06-10
• Study Start: 2025-06-11
• Last Update Submitted: 2025-06-11
• Last Update Posted: 2025-06-12
• Primary Completion: 2032-02-02
• Study Completion: 2032-02-02

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 12000

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
V181	V181	Participants will receive a single 0.5 mL subcutaneous (SC) dose of V181 on Day 1.
Placebo	Placebo	Participants will receive a single 0.5 mL SC dose of placebo on Day 1.

Primary Outcome Measures

Name	Time	Method
Percentage of Participants Experiencing a Medically Attended Adverse Event (MAAE)	Up to approximately 6 months postvaccination	A MAAE is an adverse event (AE) in which medical attention is received during an unscheduled, non-routine outpatient visit, such as an ER visit, office visit, or an urgent care visit with any medical personnel for any reason.
Percentage of Participants Experiencing a Serious Adverse Event (SAE)	Up to approximately 1 year postvaccination	An SAE is an AE that results in death, 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 Experiencing a Vaccine-Related SAE	Up to approximately 5 years postvaccination	An SAE is an AE that results in death, 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.
Reactogenicity and Immunogenicity Subset: Percentage of Participants Experiencing Solicited Injection-site AEs	Up to approximately 5 days postvaccination	An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study treatment. Solicited injection-site AEs will include pain/tenderness, erythema/redness, and swelling.
Reactogenicity and Immunogenicity Subset: Percentage of Participants Experiencing Solicited Systemic AEs	Up to approximately 28 days postvaccination	An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study treatment. Solicited systemic AEs will include rash, headache, tiredness (fatigue), muscle aches all over body (myalgia), joint pain and fever (pyrexia).
Percentage of Participants Experiencing Symptomatic (Requiring Fever on at Least 2 of 3 Consecutive Days) VCD of Any Severity, Due to Any of the 4 Dengue Serotypes, Regardless of Dengue Serostatus at Baseline	Up to approximately 3 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by wild type (WT) reverse transcription polymerase chain reaction (RT-PCR) or non-structural protein 1 (NS1) enzyme-linked immunosorbent assay (ELISA).

Secondary Outcome Measures

Name	Time	Method
Percentage of Participants Experiencing Symptomatic (Requiring Fever on at Least 2 of 3 Consecutive Days) VCD of Any Severity, Due to Each of the 4 Dengue Serotypes, Regardless of Dengue Serostatus at Baseline	Up to approximately 3 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA.
Percentage of Participants Experiencing Symptomatic (Requiring Fever on at Least 2 of 3 Consecutive Days) VCD of Any Severity, by Dengue Serostatus at Baseline, Up to Approximately 3 Years Postvaccination	Up to approximately 3 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA.
Percentage of Participants Experiencing Symptomatic (Requiring Fever on at Least 2 of 3 Consecutive Days) VCD of Any Severity, by Dengue Serostatus at Baseline, Up to Approximately 5 Years Postvaccination	Up to approximately 5 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA.
Percentage of Participants Experiencing Symptomatic (Requiring Fever on at Least 2 of 3 Consecutive Days) VCD of Any Severity, Regardless of Dengue Serostatus at Baseline	Up to approximately 5 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA.
Percentage of Participants Experiencing Symptomatic (Requiring Fever on at Least 2 of 3 Consecutive Days) VCD Meeting Criteria for Warning Signs or Severe Dengue, Regardless of Dengue Serostatus at Baseline, Up to Approximately 3 Years Postvaccination	Up to approximately 3 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA. Clinical evaluation for presence of dengue with warning signs or severe dengue will be conducted by an investigator or medically qualified designee, based on pre-specified criteria.
Percentage of Participants Experiencing Symptomatic (Requiring Fever on at Least 2 of 3 Consecutive Days) VCD Meeting Criteria for Warning Signs or Severe Dengue, by Dengue Serostatus at Baseline, Up to Approximately 3 Years Postvaccination	Up to approximately 3 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA. Clinical evaluation for presence of dengue with warning signs or severe dengue will be conducted by an investigator or medically qualified designee, based on pre-specified criteria.
Percentage of Participants Experiencing Symptomatic (Requiring Fever on at Least 2 of 3 Consecutive Days) VCD Meeting Criteria for Warning Signs or Severe Dengue, Regardless of Dengue Serostatus at Baseline, Up to Approximately 5 Years Postvaccination	Up to approximately 5 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA. Clinical evaluation for presence of dengue with warning signs or severe dengue will be conducted by an investigator or medically qualified designee, based on pre-specified criteria.
Long-term Immunogenicity Subset: Percentage of Participants who Seroconvert as measured by VRNT, Regardless of Dengue Serostatus at Baseline	Up to approximately 5 years postvaccination	Seroconversion rate for Dengue virus-neutralizing antibody titers for 4 dengue serotypes (DENV-1, DENV-2, DENV-3, DENV-4) as measured by VRNT will be reported.
Percentage of Participants Experiencing Symptomatic (Requiring Fever on at Least 2 of 3 Consecutive Days) VCD Meeting Criteria for Warning Signs or Severe Dengue, by Dengue Serostatus at Baseline, Up to Approximately 5 Years Postvaccination	Up to approximately 5 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA. Clinical evaluation for presence of dengue with warning signs or severe dengue will be conducted by an investigator or medically qualified designee, based on pre-specified criteria.
Percentage of Participants Experiencing Hospitalization Resulting from Symptomatic (Requiring Fever on at Least 2 of 3 Consecutive Days) VCD of Any Severity, Regardless of Dengue Serostatus at Baseline, Up to Approximately 3 Years Postvaccination	Up to approximately 3 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA.
Percentage of Participants Experiencing Hospitalization Resulting from Symptomatic (Requiring Fever on at Least 2 of 3 Consecutive Days) VCD of Any Severity, by Dengue Serostatus at Baseline, Up to Approximately 3 Years Postvaccination	Up to approximately 3 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA.
Percentage of Participants Experiencing Hospitalization Resulting from Symptomatic (Requiring Fever on at Least 2 of 3 Consecutive Days) VCD of Any Severity, Regardless of Dengue Serostatus at Baseline, Up to Approximately 5 Years Postvaccination	Up to approximately 5 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA.
Percentage of Participants Experiencing Hospitalization Resulting from Symptomatic (Requiring Fever on at Least 2 of 3 Consecutive Days) VCD of Any Severity, by Dengue Serostatus at Baseline, Up to Approximately 5 Years Postvaccination	Up to approximately 5 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA.
Percentage of Participants Experiencing Symptomatic (Regardless of Fever Duration) VCD of Any Severity, Regardless of Dengue Serostatus at Baseline, Up to Approximately 3 Years Postvaccination	Up to approximately 3 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA.
Percentage of Participants Experiencing Symptomatic (Regardless of Fever Duration) VCD of Any Severity, by Dengue Serostatus at Baseline, Up to Approximately 3 Years Postvaccination	Up to approximately 3 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA.
Percentage of Participants Experiencing Symptomatic (Regardless of Fever Duration) VCD of Any Severity, Regardless of Dengue Serostatus at Baseline, Up to Approximately 5 Years Postvaccination	Up to approximately 5 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA.
Percentage of Participants Experiencing Symptomatic (Regardless of Fever Duration) VCD of Any Severity, by Dengue Serostatus at Baseline, Up to Approximately 5 Years Postvaccination	Up to approximately 5 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA.
Percentage of Participants Experiencing Symptomatic (Regardless of Fever Duration) VCD Meeting Criteria for Warning Signs or Severe Dengue, Regardless of Dengue Serostatus at Baseline, Up to Approximately 3 Years Postvaccination	Up to approximately 3 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA. Clinical evaluation for presence of dengue with warning signs or severe dengue will be conducted by an investigator or medically qualified designee, based on pre-specified criteria.
Percentage of Participants Experiencing Symptomatic (Regardless of Fever Duration) VCD Meeting Criteria for Warning Signs or Severe Dengue, by Dengue Serostatus at Baseline, Up to Approximately 3 Years Postvaccination	Up to approximately 3 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA. Clinical evaluation for presence of dengue with warning signs or severe dengue will be conducted by an investigator or medically qualified designee, based on pre-specified criteria.
Percentage of Participants Experiencing Symptomatic (Regardless of Fever Duration) VCD Meeting Criteria for Warning Signs or Severe Dengue, Regardless of Dengue Serostatus at Baseline, Up to Approximately 5 Years Postvaccination	Up to approximately 5 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA. Clinical evaluation for presence of dengue with warning signs or severe dengue will be conducted by an investigator or medically qualified designee, based on pre-specified criteria.
Long-term Immunogenicity Subset: Dengue Virus-Neutralizing Antibody Titers, as Measured by VRNT, by Dengue Serostatus at Baseline	Up to approximately 5 years postvaccination	Dengue virus-neutralizing antibody titers for 4 dengue serotypes (DENV-1, DENV-2, DENV-3, DENV-4) as measured by VRNT will be reported.
Percentage of Participants Experiencing Symptomatic (Regardless of Fever Duration) VCD Meeting Criteria for Warning Signs or Severe Dengue, by Dengue Serostatus at Baseline, Up to Approximately 5 Years Postvaccination	Up to approximately 5 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA. Clinical evaluation for presence of dengue with warning signs or severe dengue will be conducted by an investigator or medically qualified designee, based on pre-specified criteria.
Percentage of Participants Experiencing Hospitalization Resulting from Symptomatic (Regardless of Fever Duration) VCD of Any Severity, Regardless of Dengue Serostatus at Baseline, Up to Approximately 3 Years Postvaccination	Up to approximately 3 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA.
Percentage of Participants Experiencing Hospitalization Resulting from Symptomatic (Regardless of Fever Duration) VCD of Any Severity, by Dengue Serostatus at Baseline, Up to Approximately 3 Years Postvaccination	Up to approximately 3 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA.
Percentage of Participants Experiencing Hospitalization Resulting from Symptomatic (Regardless of Fever Duration) VCD of Any Severity, Regardless of Dengue Serostatus at Baseline, Up to Approximately 5 Years Postvaccination	Up to approximately 5 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA.
Percentage of Participants Experiencing Hospitalization Resulting from Symptomatic (Regardless of Fever Duration) VCD of Any Severity, by Dengue Serostatus at Baseline, Up to Approximately 5 Years Postvaccination	Up to approximately 5 years postvaccination	Fever is defined as presence of body temperature ≥ 100.4 °F. Dengue status will be confirmed by WT RT-PCR or NS1 ELISA.
Reactogenicity and Immunogenicity Subset: Percentage of Participants who are Seropositive as measured by VRNT, by Dengue Serostatus at Baseline	Up to approximately 28 days postvaccination	Seropositivity for Dengue virus-neutralizing antibody titers for 4 dengue serotypes (DENV-1, DENV-2, DENV-3, DENV-4) as measured by VRNT will be reported.
Reactogenicity and Immunogenicity Subset: Percentage of Participants who are Seropositive as measured by VRNT, Regardless of Dengue Serostatus at Baseline	Up to approximately 28 days postvaccination	Seropositivity for Dengue virus-neutralizing antibody titers for 4 dengue serotypes (DENV-1, DENV-2, DENV-3, DENV-4) as measured by VRNT will be reported.
Reactogenicity and Immunogenicity Subset: Percentage of Participants who Seroconvert as measured by VRNT, by Dengue Serostatus at Baseline	Up to approximately 28 days postvaccination	Seroconversion rate for Dengue virus-neutralizing antibody titers for 4 dengue serotypes (DENV-1, DENV-2, DENV-3, DENV-4) as measured by VRNT will be reported.
Reactogenicity and Immunogenicity Subset: Percentage of Participants who Seroconvert as measured by VRNT, Regardless of Dengue Serostatus at Baseline	Up to approximately 28 days postvaccination	Seroconversion rate for Dengue virus-neutralizing antibody titers for 4 dengue serotypes (DENV-1, DENV-2, DENV-3, DENV-4) as measured by VRNT will be reported.
Reactogenicity and Immunogenicity Subset: Dengue Virus-Neutralizing Antibody Titers, as Measured by VRNT, by Dengue Serostatus at Baseline	Up to approximately 28 days postvaccination	Dengue virus-neutralizing antibody titers for 4 dengue serotypes (DENV-1, DENV-2, DENV-3, DENV-4) as measured by VRNT will be reported.
Reactogenicity and Immunogenicity Subset: Dengue Virus-Neutralizing Antibody Titers, as Measured by VRNT, Regardless of Dengue Serostatus at Baseline	Up to approximately 28 days postvaccination	Dengue virus-neutralizing antibody titers for 4 dengue serotypes (DENV-1, DENV-2, DENV-3, DENV-4) as measured by VRNT will be reported.
Reactogenicity and Immunogenicity Subset: Geometric Mean Fold Rises (GMFRs) in Dengue Virus-Neutralizing Antibody Titers, by Dengue Serostatus at Baseline	Baseline (Day 1) and up to approximately 28 days postvaccination	GMFRs for Dengue virus-neutralizing antibody titers for 4 dengue serotypes (DENV-1, DENV-2, DENV-3, DENV-4) as measured by VRNT will be reported.
Reactogenicity and Immunogenicity Subset: GMFRs in Dengue Virus-Neutralizing Antibody Titers, Regardless of Dengue Serostatus at Baseline	Baseline (Day 1) and up to approximately 28 days postvaccination	GMFRs for Dengue virus-neutralizing antibody titers for 4 dengue serotypes (DENV-1, DENV-2, DENV-3, DENV-4) as measured by VRNT will be reported.
Long-term Immunogenicity Subset: Percentage of Participants who are Seropositive, as measured by VRNT, by Dengue Serostatus at Baseline	Up to approximately 5 years postvaccination	Seropositivity for Dengue virus-neutralizing antibody titers for 4 dengue serotypes (DENV-1, DENV-2, DENV-3, DENV-4) as measured by VRNT will be reported.
Long-term Immunogenicity Subset: Percentage of Participants who are Seropositive, as measured by VRNT, Regardless of Dengue Serostatus at Baseline	Up to approximately 5 years postvaccination	Seropositivity for Dengue virus-neutralizing antibody titers for 4 dengue serotypes (DENV-1, DENV-2, DENV-3, DENV-4) as measured by VRNT will be reported.
Long-term Immunogenicity Subset: Percentage of Participants who Seroconvert, as measured by VRNT, by Dengue Serostatus at Baseline	Up to approximately 5 years postvaccination	Seroconversion rate for Dengue virus-neutralizing antibody titers for 4 dengue serotypes (DENV-1, DENV-2, DENV-3, DENV-4) as measured by VRNT will be reported.
Long-term Immunogenicity Subset: Dengue Virus-Neutralizing Antibody Titers, as Measured by VRNT, Regardless of Dengue Serostatus at Baseline	Up to approximately 5 years postvaccination	Dengue virus-neutralizing antibody titers for 4 dengue serotypes (DENV-1, DENV-2, DENV-3, DENV-4) as measured by VRNT will be reported.

Trial Locations

Locations (2)

National University Hospital-Paediatrics ( Site 0001); 🇸🇬 Singapore, Central Singapore, Singapore

Tan Tock Seng Hospital ( Site 0003); 🇸🇬 Singapore, Central Singapore, Singapore