Study on a Live-attenuated Respiratory Syncytial Virus Vaccine for Assessment of Safety, Transmissibility, and Genetic Stability of the Vaccine Virus Among Close Contacts in Infants and Toddlers 6 to < 24 Months of Age in Puerto Rico (USA)

NCT ID: NCT05687279

Last Updated: 2026-01-26

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE1/PHASE2
• Total Enrollment: 80 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-02-06
• Study Completion Date: 2024-12-27

Brief Summary

The primary purpose of the study is to assess the shedding, transmission, and genetic stability of the live-attenuated RSVt vaccine after each intranasal vaccination (56 days apart) in infants and toddlers 6 to < 24 months of age.

Detailed Description

The duration of each participant's participation is up to 8 months, including the 6 months safety follow-up phone call after the second study intervention administration for the pediatric participants The treatment administration for the pediatric participants will be on D01 and D57 (1 intranasal administration each).

Conditions

Respiratory Syncytial Virus Infection

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: QUADRUPLE

Study Groups

RSVt Vaccine Group

2 intranasal administrations (56 days apart) of the RSVt vaccine at D01 and D57

Group Type: EXPERIMENTAL

RSVt Vaccine

Intervention Type: BIOLOGICAL

Pharmaceutical Form: Suspension of virus in a nasal spray Route of Administration: Intranasal

Control Group

2 intranasal administrations (56 days apart) of the placebo at D01 and D57

Group Type: PLACEBO_COMPARATOR

Control Group

Intervention Type: OTHER

Pharmaceutical Form: Suspension of virus in a nasal spray Route of Administration: Intranasal

Interventions

RSVt Vaccine

Pharmaceutical Form: Suspension of virus in a nasal spray Route of Administration: Intranasal

Intervention Type: BIOLOGICAL

Control Group

Pharmaceutical Form: Suspension of virus in a nasal spray Route of Administration: Intranasal

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Aged 6 months to < 24 months on the day of inclusion (from the day of the 6 months after birth to the day before the 2nd birthday)
• Participants who are healthy as determined by medical evaluation including medical history.
• Born at full term of pregnancy (≥ 37 weeks) or born after a gestation period of 27 through 36 weeks and medically stable as assessed by the investigator, based on the following definition: "Medically stable" refers to the condition of premature infants who do not require significant medical support or ongoing management for debilitating disease and who have demonstrated a clinical course of sustained recovery by the time they receive the first dose of study intervention
• Attends a daycare facility at least 3 days per week and 4 hours per day at which the participant would be in a contact group/playroom of at least one other child 6 to < 24 months of age who will participate in this study or is a member of a household, which includes at least one other child 6 to < 24 months of age who will participate in this study

Exclusion Criteria

• Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months)
• Known systemic hypersensitivity to any of the study intervention components, or history of a life-threatening reaction to the study intervention used in the study or to a product containing any of the same substances
• Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with study conduct or completion
• Any acute febrile illness in the past 48 hours that according to investigator judgment is significant enough to interfere with successful inoculation on the day of vaccination. A prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided.
• Probable or confirmed ongoing case of COVID-19 at the time of enrollment
• Member of a household that contains an immunocompromised individual, including, but not limited to:

• a person who is HIV infected
• a person who has received chemotherapy within the 12 months prior to study enrollment
• a person who has received (within the past 6 months) or is receiving (at the time of enrollment) immunosuppressant agents
• a person living with a solid organ or bone marrow transplant
• Member of a household that includes, or will include, an infant who is less than 6 months of age at the time of enrollment
• Attends a daycare facility and shares a daycare room with infants less than 6 months of age, and parent/legally acceptable representative is unable or unwilling to suspend attendance at the daycare facility for 28 days following study intervention administration
• Any need of supplemental oxygen therapy in a home or hospital setting at the time of enrollment.
• Participant's mother previous receipt or planned administration of an investigational RSV vaccine or any monoclonal antibody (such as Infliximab) during pregnancy and/or breastfeeding.
• Receipt or planned receipt of any of the following vaccines prior to or after the first study intervention administration:

• any influenza vaccine within 7 days prior to and after, or any COVID-19 or inactivated vaccine or live-attenuated rotavirus vaccine within 14 days prior to and after, or
• any live vaccine, other than rotavirus vaccine, within 28 days prior to and after
• Previous receipt of an investigational RSV vaccine or receiving any anti-RSV product (such as ribavirin or RSV Immunoglobulin (IG) or RSV monoclonal antibody) at the time of enrollment.
• Receipt of immune globulins, blood or blood-derived products in the past 3 months
• Receipt of intranasal and intra-ocular medications within 3 days prior to study enrollment
• Receipt at the time of enrollment or previous receipt of salicylate (aspirin) or salicylate-containing products
• 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
• Deprived of freedom in an emergency setting, or hospitalized involuntarily
• Identified as a natural or adopted child of the Investigator or employee with direct involvement in the proposed study

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

• Minimum Eligible Age: 6 Months
• Maximum Eligible Age: 23 Months
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Sanofi Pasteur, a Sanofi Company

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Clinical Sciences & Operations

Role: STUDY_DIRECTOR

Sanofi Pasteur, a Sanofi Company

Locations

Meridian Clinical Research Norfolk Site Number : 8400003

Norfolk, Nebraska, United States

Velocity Clinical Research, Omaha Site Number : 8400001

Omaha, Nebraska, United States

Investigational Site Number : 6300004

Bayamón, , Puerto Rico

Investigational Site Number : 6300002

Carolina, , Puerto Rico

Investigational Site Number : 6300003

Guayama, , Puerto Rico

Investigational Site Number : 6300001

San Juan, , Puerto Rico

Countries

United States; Puerto Rico

Provided Documents

Document Type: Study Protocol

View Document

Document Type: Statistical Analysis Plan

View Document

Other Identifiers

U1111-1278-3910

Identifier Type: REGISTRY

Identifier Source: secondary_id

VAD00014

Identifier Type: -

Identifier Source: org_study_id