Phase II, Randomized, Observer-blind, Placebo-controlled, Multi-center Study of a Live Attenuated Respiratory Syncytial Virus Vaccine to Assess the Vaccine Virus' Transmissibility in Household or Daycare Center Settings, Shedding, and Genetic Stability, and to Describe the Immunogenicity and Safety of the Vaccine in Infants and Toddlers 6 to < 24 Months of Age in Puerto Rico (USA)
试验速览
- 阶段
- 1 期
- 状态
- 已完成
- 入组人数
- 80
- 试验地点
- 6
- 主要终点
- Percentage of Placebo Receiving Pediatric Participants With Vaccine Virus Detected in Nasal Swabs After the First Vaccination
研究概览
简要总结
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.
详细描述
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).
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Prevention
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
盲法说明
Observer-blind:
- Blinding for vaccine group assignment: participants, parents or legally acceptable representative (LAR), outcome assessors, investigators, laboratory personnel, Sponsor study staff
- No blinding for study staff who prepare and administer the study interventions
入排标准
- 年龄范围
- 6 Months 至 23 Months（Child）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •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
排除标准
- •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.
研究组 & 干预措施
Control Group
2 intranasal administrations (56 days apart) of the placebo at D01 and D57
干预措施: Control Group (Other)
RSVt Vaccine Group
2 intranasal administrations (56 days apart) of the RSVt vaccine at D01 and D57
干预措施: RSVt Vaccine (Biological)
结局指标
主要结局
Percentage of Placebo Receiving Pediatric Participants With Vaccine Virus Detected in Nasal Swabs After the First Vaccination
时间窗: Pre-vaccination on Day 1 and post-vaccination on Days 4, 8, 11, 15, 18 and 22
Nasal swabs were collected to assess the presence of vaccine virus after first vaccination. Vaccine virus transmission was defined as presence of detected vaccine virus confirmed by RSVt quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay (vaccine virus shedding \>=lower limit of detection \[LOD=2.80 log10 copies/mL\]) in pediatric participants receiving placebo. Percentages are rounded off to the tenth decimal place.
Titer of Vaccine Virus Shedding in All Pediatric Participants Detected in Nasal Swabs
时间窗: Pre-vaccination on Day 1 and post-vaccination on Days 4, 8, 11, 15, 18, 22, 64 and 71
Nasal swabs were collected to assess the shedding of the attenuated RSV vaccine strain and quantified by RSVt qRT PCR assay. Quantified virus shedding was defined as vaccine virus shedding \>=lower limit of quantification (LLOQ=3.37 log10 copies/mL).
Percentage of Placebo Receiving Pediatric Participants With Detected Shedding Who Showed Any Genetic Sequence Variation After Each Vaccination
时间窗: Up to 21 days after each vaccination (Day 1 to Day 22 and Day 57 to Day 78)
Nasal swabs were collected to identify the difference in genetic sequence of mutated vaccine virus segments compared to the reference strain vaccine virus isolates in the vaccine virus positive swabs from pediatric participants receiving placebo after each vaccination. Detected virus shedding was defined as vaccine virus shedding \>=LOD (2.80 log10 copies/mL).
次要结局
- Geometric Mean Titers (GMTs) of RSV A Serum Neutralizing Antibody (nAb) Titers(Pre-vaccination on Day 1 (first vaccination) and Day 57 (second vaccination) and up to 28 days after second vaccination, Day 85)
- Secondary: Geometric Mean Titers of RSV Serum Anti-F Immunoglobulin G (IgG) Enzyme-linked Immuno-adsorbant Assay (ELISA) Antibody(Pre-vaccination on Day 1 (first vaccination) and Day 57 (second vaccination) and up to 28 days after second vaccination, Day 85)
- Number of Participants With Immediate Unsolicited Adverse Events (AEs)(Up to 30 minutes after each vaccination (Days 1 and 57))
- Number of Participants With Solicited Administration Site Reactions and Systemic Reactions(Up to 21 days after each vaccination (Day 1 to Day 22 and Day 57 to Day 78))
- Number of Participants With Unsolicited Adverse Events(Up to 28 days after each vaccination (Day 1 to Day 29 and Day 57 to Day 85))