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)

Sanofi

Status and phase: Completed; Phase 2; Phase 1

Conditions: Respiratory Syncytial Virus Infection

Treatments: Biological: RSVt Vaccine; Other: Control Group

Study type: Interventional

Funder types: Industry

Identifiers

NCT05687279

U1111-1278-3910 (Registry Identifier)

VAD00014

Details and patient eligibility

About

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.

Full 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).

Enrollment: 80 patients

Sex: All

Ages: 6 to 23 months old

Volunteers: Accepts Healthy Volunteers

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.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

---

80 participants in 2 patient groups, including a placebo group

RSVt Vaccine Group

Experimental group

Description:

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

Treatment:

Biological: RSVt Vaccine

Control Group

Placebo Comparator group

Description:

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

Treatment:

Other: Control Group