Respiratory Syncytial Virus Infection
Conditions
Brief summary
The primary objectives of the study were: * To assess the safety profile of each dose of the study product after each and any administration in all infants and toddlers regardless of baseline serostatus. * To characterize the Respiratory Syncytial Virus (RSV) A serum neutralizing antibody responses to the study product in each vaccine group after vaccination in RSV-naïve participants. The secondary objectives of the study were: * To quantify the amount of vaccine virus shed by each participant by baseline serostatus. * To determine the proportion of vaccinated infants and toddlers in each vaccine group infected with the vaccine virus at D56 (56 days after vaccination 1) for Cohorts 1, 2, 3 and 4, and at Day 84 (28 days after vaccination 2) for Cohorts 2 and 4 by baseline serostatus. * To characterize the RSV A serum neutralizing antibody responses to the study product in each vaccine group after vaccination in RSV-experienced participants. * To characterize serum RSV anti-F immunoglobulin G (IgG) antibody responses to the study product in each vaccine group after vaccination by baseline serostatus. * To characterize serum RSV antibody responses (RSV A-neutralizing and anti-RSV F IgG) to the study product in each vaccine group after the RSV surveillance season or at least 5 months after the last vaccine administration by baseline serostatus.
Detailed description
Study duration per participant was maximum 12 months
Interventions
BIOLOGICALRSV vaccine formulation 1
Pharmaceutical form: Suspension of virus Route of administration: Intranasal
BIOLOGICALRSV vaccine formulation 2
Pharmaceutical form: Suspension of virus Route of administration: Intranasal
BIOLOGICALPlacebo
Pharmaceutical form: Suspension Route of administration: Intranasal
Sponsors
Sanofi Pasteur, a Sanofi Company
Study design
Allocation
RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
PREVENTION
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Masking description
The study was performed in an observer-blind fashion. Investigators and study staff who conducted the safety assessment and the participants did not know which vaccine is administered. Only the study staff who prepare and administer the vaccine and were not involved with the safety evaluation knew which vaccine was administered.
Eligibility
Sex/Gender
ALL
Age
6 Months to 18 Months
Healthy volunteers
Yes
Inclusion criteria
Inclusion criteria : * Aged 6 through 18 months at Day 0. * Informed consent form has been signed and dated by the parent(s) or other legally acceptable representative (and by independent witness if required by local regulations). * Participant and parent / guardian / legally acceptable representative are able to attend all scheduled visits and to comply with all trial procedures
Exclusion criteria
* Born at less than 34 weeks gestation * Born at less than 37 weeks gestation and less than 1 year of age at the time * 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). * Probable or confirmed case of Coronavirus Disease 2019 (COVID-19). * Known systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to the vaccine used in the trial or to a vaccine containing any of the same substances * Any chronic illness • Chronic illness may include, but is not limited to, cardiac disorders, lung disease (including any history of reactive airway disease, receipt of bronchodilator therapy, or medically diagnosed wheezing), renal disorders, auto-immune disorders, diabetes, psychomotor diseases, and known congenital or genetic diseases * Any history of medically diagnosed wheezing * Any acute febrile, respiratory or gastrointestinal illness in the past 24 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 * Any previous anaphylactic reaction * Current suspected or documented developmental disorder, delay, or other developmental problem * Receipt of any of the following vaccines prior to enrollment: * any influenza vaccine within 7 days prior, or * any inactivated vaccine or live-attenuated rotavirus vaccine within the 14 days prior, or * any live vaccine, other than rotavirus vaccine, within the 28 days prior, or * another investigational vaccine or investigational drug within 28 days prior * Previous receipt of a licensed or investigational RSV vaccine or previous receipt or planned administration of any anti-RSV product (such as ribavirin or RSV immune immune globulins \[IG\] or RSV monoclonal antibody) * Receipt of immune globulins, blood or blood-derived products in the past 6 months prior to enrolment * Receipt of any of the following medications within 3 days prior to study enrollment (Day 0): * systemic antibacterial, antiviral, antifungal, anti-parasitic, or antituberculous agents, whether for treatment or prophylaxis, or * intranasal medications, or * other prescription medication except as permitted concomitant medications (prescription or non-prescription) including nutritional supplements, medications for gastroesophageal reflux, eye drops, and topical medications, including (but not limited to) cutaneous (topical) steroids, topical antibiotics, and topical antifungal agents * Receipt of salicylate (aspirin) or salicylate-containing products within the 28 days prior to enrollment (Day 0) * Any previous vaccine-associated adverse reaction that was Grade 3 or above. Note: if grading is not possible, determine if the reaction was considered severe or life threatening; if so, it is exclusionary. * Scheduled administration of the following after planned inoculation: * any influenza vaccine within 7 days after, or * inactivated vaccine or live-attenuated rotavirus vaccine within the 14 days after, or * any live vaccine other than rotavirus in the 28 days after, or * another investigational vaccine or investigational drug in the 56 days after. * Any previous receipt of supplemental oxygen therapy in a home or hospital setting, except the temporary receipt of supplemental oxygen for transient tachypnea in newborn * 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 enrollment * a person receiving immunosuppressant agents * a person living with a solid organ or bone marrow transplant * Participation at the time of study enrollment (or in the 6 weeks preceding the first trial vaccination) or planned participation during the present trial period in another clinical trial investigating a vaccine, drug, medical device, or medical procedure * Member of a household that contains, or will contain, an infant who is less than 6 months of age at the enrollment date (or in the 6 weeks preceding the first trial vaccination) through Day 28 * Member of a household that contains another child/other children who is/are, or is/are scheduled to be, enrolled in this study in the same year AND the date of enrollment will not be concurrent with the other participant(s) living in the household (i.e., all eligible children from the same household must be enrolled on the same date) * Attends a daycare facility and shares a daycare room with infants less than 6 months of age, and parent/guardian is unable or unwilling to suspend daycare for 28 days following inoculation * 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 was not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Naïve Participants | Cohorts 1 and 3: Day 56; Cohorts 2 and 4: Days 56 and 84 | RSV A neutralizing antibody measured by microneutralization. RSV-naïve participants are defined as undetectable serum anti-RSV A IgA antibodies. |
| Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs) | Cohorts 1 and 3: Within 30 minutes after vaccination on Day 0; Cohorts 2 and 4: Within 30 minutes after vaccination on Days 0 and 56 | An AE is any untoward medical occurrence in a participant or in a clinical investigation participant administered a medicinal product and which does not necessarily have a causal relationship with this treatment. An unsolicited AE is an observed AE that does not fulfill the conditions pre-listed in the case report book (CRB) in terms of diagnosis and/or onset window post-vaccination. Systemic AEs are all AEs that were not injection or administration site reactions. Immediate events are recorded to capture medically relevant unsolicited systemic AEs (including those related to the product administered) that occur within the first 30 minutes after vaccination. |
| Number of Participants With Solicited Administration Site and Systemic Reactions | Cohorts 1 and 3: Within 28 days after vaccination on Day 0; Cohorts 2 and 4: Within 28 days after vaccination on Days 0 and 56 | All noxious and unintended responses to a medicinal product related to any dose are considered adverse reactions (AR). A solicited reaction is an expected AR (sign or symptom) observed and reported under the conditions (nature and onset) pre-listed in the protocol and CRB. An administration site reaction is an AR at and around the administration site. Systemic ARs are all ARs that are not injection or administration site reactions. |
| Number of Participants With Unsolicited Adverse Events | Cohorts 1 and 3: Within 28 days after vaccination on Day 0; Cohorts 2 and 4: Within 28 days after vaccination on Days 0 and 56 | An AE is any untoward medical occurrence in a participant or in a clinical investigation participant administered a medicinal product and which does not necessarily have a causal relationship with this treatment. An unsolicited AE is an observed AE that does not fulfill the conditions pre-listed in the CRB in terms of diagnosis and/or onset window post-vaccination. |
| Number of Participants With Adverse Events of Special Interest (AESIs) | Cohorts 1 and 3: Within 28 days after vaccination on Day 0; Cohorts 2 and 4: Within 28 days after vaccination on Days 0 and 56 | An AESI is one of scientific and medical concern specific to the Sponsor's product or program, for which ongoing monitoring and rapid communication by the investigator to the sponsor can be appropriate. |
| Number of Participants With Medically Attended Adverse Events (MAAEs) | Cohorts 1 and 3: Within 28 days after vaccination on Day 0; Cohorts 2 and 4: Within 28 days after vaccination on Days 0 and 56 | An MAAE is a new onset or a worsening of a condition that prompts the participant or participant's parent/guardian/legally authorized representative to seek unplanned medical advice at a physician's office or Emergency Department. |
| Number of Participants With Serious Adverse Events (SAEs) | From the first study vaccine administration (Day 0) up to end of the study, maximum of 12 months | An SAE is any untoward medical occurrence that at any dose results in death or is life-threatening or requires inpatient hospitalization or prolongation of existing hospitalization or results in persistent or significant disability/incapacity or is a congenital anomaly/birth defect or is an important medical event. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Percentage of Participants Infected With Vaccine Virus at Days 56 and 84 | Cohorts 1 and 3: Day 56; Cohorts 2 and 4: Days 56 and 84 | Infection is defined as detection of vaccine virus in nasal swab by RT-PCR and/or a \>= 4-fold rise in RSV A serum neutralizing antibody titers, or in RSV serum anti-F immunoglobulin G (IgG) antibody titers. |
| Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Experienced Participants | Cohorts 1 and 3: Day 56; Cohorts 2 and 4: Days 56 and 84 | RSV A neutralizing antibody measured by microneutralization. RSV-experienced participants are defined as detectable serum anti-RSV A IgA antibodies. CI= confidence interval. |
| Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | Cohorts 1 and 3: Day 56; Cohorts 2 and 4: Days 56 and 84 | The IgG antibodies to RSV F antigen was measured using the anti RSV F IgG ELISA. RSV-naïve and RSV-experienced participants are defined as undetectable or detectable serum anti-RSV A IgA antibodies, respectively. |
| Geometric Mean Titers Against RSV A Neutralizing Antibody After the RSV Surveillance Season | Cohorts 1 and 3: Within 5 months after vaccination on Day 0; Cohorts 2 and 4: Within 5 months after vaccination on Day 56 | RSV A neutralizing antibody measured by microneutralization. RSV-naïve and RSV-experienced participants are defined as undetectable or detectable serum anti-RSV A IgA antibodies, respectively. |
| Geometric Mean Titers Against Serum Anti-F Immunoglobulin G Antibody After the RSV Surveillance Season | Cohorts 1 and 3: Within 5 months after vaccination on Day 0; Cohorts 2 and 4: Within 5 months after vaccination on Day 56 | The IgG antibodies to RSV F antigen was measured using the anti RSV F IgG ELISA. RSV-naïve and RSV-experienced participants are defined as undetectable or detectable serum anti-RSV A IgA antibodies, respectively. |
| Titer of Vaccine Virus Shedding Measured by Reverse Transcription Polymerase Chain Reaction (RT-PCR) | Cohorts 1 and 3: Day 7; Cohorts 2 and 4: Days 7 and 63 | Shedding of the attenuated RSV vaccine strain in nasal swab samples was evaluated by RSV quantitative RT-PCR (qRT-PCR) assay, which specifically detected and quantified RSVt ΔNS2 vaccine strain (RSV ΔNS2/Δ1313/I1314L) in human nasal swab samples. |
Countries
Chile, Honduras, United States
Participant flow
Recruitment details
The study was conducted at 26 centers in the United States, Chile and Honduras between 17 September 2020 and 13 April 2023.
Pre-assignment details
A total of 259 participants were enrolled and randomized in the study.
Participants by arm
| Arm | Count |
|---|---|
| Cohort 1: RSV Low Dose Participants received a single low dose intranasal spray of RSVt on Day 0. | 18 |
| Cohort 1: Placebo Participants received a single intranasal spray of placebo on Day 0. | 18 |
| Cohort 2: RSV Low Dose Participants received low dose RSVt intranasal spray once daily on Days 0 and 56. | 11 |
| Cohort 2: Placebo Participants received placebo intranasal spray once daily on Days 0 and 56. | 10 |
| Cohort 3: RSV High Dose Participants received a single high dose intranasal spray of RSVt on Day 0. | 10 |
| Cohort 3: Placebo Participants received a single intranasal spray of placebo on Day 0. | 12 |
| Cohort 4: RSV Low Dose Participants received low dose RSVt intranasal spray once daily on Days 0 and 56. | 61 |
| Cohort 4: RSV High Dose Participants received high dose RSVt intranasal spray once daily on Days 0 and 56. | 58 |
| Cohort 4: Placebo Participants received placebo intranasal spray once daily on Days 0 and 56. | 61 |
| Total | 259 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 | FG003 | FG004 | FG005 | FG006 | FG007 | FG008 |
|---|---|---|---|---|---|---|---|---|---|---|
| Overall Study | Lost to Follow-up | 0 | 2 | 0 | 0 | 0 | 0 | 2 | 1 | 1 |
| Overall Study | Protocol Deviation | 1 | 0 | 2 | 0 | 0 | 0 | 1 | 1 | 0 |
| Overall Study | Withdrawal by Parent/Guardian | 0 | 0 | 0 | 2 | 0 | 2 | 2 | 5 | 3 |
Baseline characteristics
| Characteristic | Cohort 1: RSV Low Dose | Cohort 1: Placebo | Cohort 2: RSV Low Dose | Cohort 2: Placebo | Cohort 3: RSV High Dose | Cohort 3: Placebo | Cohort 4: RSV Low Dose | Cohort 4: RSV High Dose | Cohort 4: Placebo | Total |
|---|---|---|---|---|---|---|---|---|---|---|
| Age, Continuous | 11.2 months STANDARD_DEVIATION 4.51 | 11.8 months STANDARD_DEVIATION 3.09 | 11.4 months STANDARD_DEVIATION 4.01 | 10.8 months STANDARD_DEVIATION 4.13 | 12.1 months STANDARD_DEVIATION 3.11 | 12.8 months STANDARD_DEVIATION 3.95 | 10.4 months STANDARD_DEVIATION 3.17 | 10.6 months STANDARD_DEVIATION 3.63 | 10.6 months STANDARD_DEVIATION 3.78 | 10.9 months STANDARD_DEVIATION 3.63 |
| Race/Ethnicity, Customized American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 10 Participants | 11 Participants | 9 Participants | 30 Participants |
| Race/Ethnicity, Customized Asian | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race/Ethnicity, Customized Black or African American | 1 Participants | 2 Participants | 0 Participants | 0 Participants | 0 Participants | 2 Participants | 1 Participants | 3 Participants | 1 Participants | 10 Participants |
| Race/Ethnicity, Customized Mixed Origin | 1 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 8 Participants | 9 Participants | 13 Participants | 31 Participants |
| Race/Ethnicity, Customized Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 1 Participants |
| Race/Ethnicity, Customized Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race/Ethnicity, Customized Unknown | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race/Ethnicity, Customized White | 16 Participants | 16 Participants | 11 Participants | 10 Participants | 10 Participants | 10 Participants | 41 Participants | 35 Participants | 38 Participants | 187 Participants |
| Sex: Female, Male Female | 8 Participants | 11 Participants | 4 Participants | 5 Participants | 4 Participants | 3 Participants | 31 Participants | 25 Participants | 32 Participants | 123 Participants |
| Sex: Female, Male Male | 10 Participants | 7 Participants | 7 Participants | 5 Participants | 6 Participants | 9 Participants | 30 Participants | 33 Participants | 29 Participants | 136 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk | EG004 affected / at risk | EG005 affected / at risk | EG006 affected / at risk | EG007 affected / at risk | EG008 affected / at risk |
|---|---|---|---|---|---|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 17 | 0 / 18 | 0 / 10 | 0 / 10 | 0 / 10 | 0 / 12 | 0 / 61 | 0 / 57 | 0 / 61 |
| other Total, other adverse events | 15 / 17 | 17 / 18 | 10 / 10 | 9 / 10 | 9 / 10 | 10 / 12 | 55 / 61 | 49 / 57 | 59 / 61 |
| serious Total, serious adverse events | 0 / 17 | 0 / 18 | 1 / 10 | 0 / 10 | 0 / 10 | 1 / 12 | 2 / 61 | 1 / 57 | 2 / 61 |
Outcome results
Primary
Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Naïve Participants
RSV A neutralizing antibody measured by microneutralization. RSV-naïve participants are defined as undetectable serum anti-RSV A IgA antibodies.
Time frame: Cohorts 1 and 3: Day 56; Cohorts 2 and 4: Days 56 and 84
Population: The full analysis set (FAS) included all randomized participants who received at least 1 administration of the study vaccine. Only participants analyzed at each specific time point are reported.
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| Cohort 1: RSV Low Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Naïve Participants | Day 56 | 75.9 titer |
| Cohort 1: Placebo | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Naïve Participants | Day 56 | 32.8 titer |
| Cohort 2: RSV Low Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Naïve Participants | Day 84 | 181 titer |
| Cohort 2: RSV Low Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Naïve Participants | Day 56 | 180 titer |
| Cohort 2: Placebo | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Naïve Participants | Day 84 | 19.8 titer |
| Cohort 2: Placebo | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Naïve Participants | Day 56 | 27.5 titer |
| Cohort 3: RSV High Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Naïve Participants | Day 56 | 99.2 titer |
| Cohort 3: Placebo | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Naïve Participants | Day 56 | 17.9 titer |
| Cohort 4: RSV Low Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Naïve Participants | Day 56 | 83.7 titer |
| Cohort 4: RSV Low Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Naïve Participants | Day 84 | 142 titer |
| Cohort 4: RSV High Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Naïve Participants | Day 56 | 79.4 titer |
| Cohort 4: RSV High Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Naïve Participants | Day 84 | 107 titer |
| Cohort 4: Placebo | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Naïve Participants | Day 84 | 26.3 titer |
| Cohort 4: Placebo | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Naïve Participants | Day 56 | 20.6 titer |
Primary
Number of Participants With Adverse Events of Special Interest (AESIs)
An AESI is one of scientific and medical concern specific to the Sponsor's product or program, for which ongoing monitoring and rapid communication by the investigator to the sponsor can be appropriate.
Time frame: Cohorts 1 and 3: Within 28 days after vaccination on Day 0; Cohorts 2 and 4: Within 28 days after vaccination on Days 0 and 56
Population: The SafAS included participants who received at least 1 administration of the study vaccine.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Cohort 1: RSV Low Dose | Number of Participants With Adverse Events of Special Interest (AESIs) | 3 Participants |
| Cohort 1: Placebo | Number of Participants With Adverse Events of Special Interest (AESIs) | 0 Participants |
| Cohort 2: RSV Low Dose | Number of Participants With Adverse Events of Special Interest (AESIs) | 0 Participants |
| Cohort 2: Placebo | Number of Participants With Adverse Events of Special Interest (AESIs) | 0 Participants |
| Cohort 3: RSV High Dose | Number of Participants With Adverse Events of Special Interest (AESIs) | 0 Participants |
| Cohort 3: Placebo | Number of Participants With Adverse Events of Special Interest (AESIs) | 1 Participants |
| Cohort 4: RSV Low Dose | Number of Participants With Adverse Events of Special Interest (AESIs) | 20 Participants |
| Cohort 4: RSV High Dose | Number of Participants With Adverse Events of Special Interest (AESIs) | 11 Participants |
| Cohort 4: Placebo | Number of Participants With Adverse Events of Special Interest (AESIs) | 20 Participants |
Primary
Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs)
An AE is any untoward medical occurrence in a participant or in a clinical investigation participant administered a medicinal product and which does not necessarily have a causal relationship with this treatment. An unsolicited AE is an observed AE that does not fulfill the conditions pre-listed in the case report book (CRB) in terms of diagnosis and/or onset window post-vaccination. Systemic AEs are all AEs that were not injection or administration site reactions. Immediate events are recorded to capture medically relevant unsolicited systemic AEs (including those related to the product administered) that occur within the first 30 minutes after vaccination.
Time frame: Cohorts 1 and 3: Within 30 minutes after vaccination on Day 0; Cohorts 2 and 4: Within 30 minutes after vaccination on Days 0 and 56
Population: The Safety analysis set (SafAS) included participants who received at least 1 administration of the study vaccine.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Cohort 1: RSV Low Dose | Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs) | 0 Participants |
| Cohort 1: Placebo | Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs) | 0 Participants |
| Cohort 2: RSV Low Dose | Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs) | 0 Participants |
| Cohort 2: Placebo | Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs) | 0 Participants |
| Cohort 3: RSV High Dose | Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs) | 0 Participants |
| Cohort 3: Placebo | Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs) | 0 Participants |
| Cohort 4: RSV Low Dose | Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs) | 0 Participants |
| Cohort 4: RSV High Dose | Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs) | 0 Participants |
| Cohort 4: Placebo | Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs) | 1 Participants |
Primary
Number of Participants With Medically Attended Adverse Events (MAAEs)
An MAAE is a new onset or a worsening of a condition that prompts the participant or participant's parent/guardian/legally authorized representative to seek unplanned medical advice at a physician's office or Emergency Department.
Time frame: Cohorts 1 and 3: Within 28 days after vaccination on Day 0; Cohorts 2 and 4: Within 28 days after vaccination on Days 0 and 56
Population: The SafAS included participants who received at least 1 administration of the study vaccine.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Cohort 1: RSV Low Dose | Number of Participants With Medically Attended Adverse Events (MAAEs) | 3 Participants |
| Cohort 1: Placebo | Number of Participants With Medically Attended Adverse Events (MAAEs) | 1 Participants |
| Cohort 2: RSV Low Dose | Number of Participants With Medically Attended Adverse Events (MAAEs) | 0 Participants |
| Cohort 2: Placebo | Number of Participants With Medically Attended Adverse Events (MAAEs) | 4 Participants |
| Cohort 3: RSV High Dose | Number of Participants With Medically Attended Adverse Events (MAAEs) | 0 Participants |
| Cohort 3: Placebo | Number of Participants With Medically Attended Adverse Events (MAAEs) | 1 Participants |
| Cohort 4: RSV Low Dose | Number of Participants With Medically Attended Adverse Events (MAAEs) | 36 Participants |
| Cohort 4: RSV High Dose | Number of Participants With Medically Attended Adverse Events (MAAEs) | 29 Participants |
| Cohort 4: Placebo | Number of Participants With Medically Attended Adverse Events (MAAEs) | 36 Participants |
Primary
Number of Participants With Serious Adverse Events (SAEs)
An SAE is any untoward medical occurrence that at any dose results in death or is life-threatening or requires inpatient hospitalization or prolongation of existing hospitalization or results in persistent or significant disability/incapacity or is a congenital anomaly/birth defect or is an important medical event.
Time frame: From the first study vaccine administration (Day 0) up to end of the study, maximum of 12 months
Population: The SafAS included participants who received at least 1 administration of the study vaccine.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Cohort 1: RSV Low Dose | Number of Participants With Serious Adverse Events (SAEs) | 0 Participants |
| Cohort 1: Placebo | Number of Participants With Serious Adverse Events (SAEs) | 0 Participants |
| Cohort 2: RSV Low Dose | Number of Participants With Serious Adverse Events (SAEs) | 1 Participants |
| Cohort 2: Placebo | Number of Participants With Serious Adverse Events (SAEs) | 0 Participants |
| Cohort 3: RSV High Dose | Number of Participants With Serious Adverse Events (SAEs) | 0 Participants |
| Cohort 3: Placebo | Number of Participants With Serious Adverse Events (SAEs) | 1 Participants |
| Cohort 4: RSV Low Dose | Number of Participants With Serious Adverse Events (SAEs) | 2 Participants |
| Cohort 4: RSV High Dose | Number of Participants With Serious Adverse Events (SAEs) | 1 Participants |
| Cohort 4: Placebo | Number of Participants With Serious Adverse Events (SAEs) | 2 Participants |
Primary
Number of Participants With Solicited Administration Site and Systemic Reactions
All noxious and unintended responses to a medicinal product related to any dose are considered adverse reactions (AR). A solicited reaction is an expected AR (sign or symptom) observed and reported under the conditions (nature and onset) pre-listed in the protocol and CRB. An administration site reaction is an AR at and around the administration site. Systemic ARs are all ARs that are not injection or administration site reactions.
Time frame: Cohorts 1 and 3: Within 28 days after vaccination on Day 0; Cohorts 2 and 4: Within 28 days after vaccination on Days 0 and 56
Population: The SafAS included participants who received at least 1 administration of the study vaccine. Only participants with available data are reported.
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Cohort 1: RSV Low Dose | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited administration site reactions | 15 Participants |
| Cohort 1: RSV Low Dose | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited systemic reactions | 14 Participants |
| Cohort 1: Placebo | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited administration site reactions | 12 Participants |
| Cohort 1: Placebo | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited systemic reactions | 16 Participants |
| Cohort 2: RSV Low Dose | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited administration site reactions | 8 Participants |
| Cohort 2: RSV Low Dose | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited systemic reactions | 9 Participants |
| Cohort 2: Placebo | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited administration site reactions | 7 Participants |
| Cohort 2: Placebo | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited systemic reactions | 9 Participants |
| Cohort 3: RSV High Dose | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited administration site reactions | 9 Participants |
| Cohort 3: RSV High Dose | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited systemic reactions | 9 Participants |
| Cohort 3: Placebo | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited systemic reactions | 9 Participants |
| Cohort 3: Placebo | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited administration site reactions | 6 Participants |
| Cohort 4: RSV Low Dose | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited systemic reactions | 50 Participants |
| Cohort 4: RSV Low Dose | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited administration site reactions | 53 Participants |
| Cohort 4: RSV High Dose | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited administration site reactions | 44 Participants |
| Cohort 4: RSV High Dose | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited systemic reactions | 46 Participants |
| Cohort 4: Placebo | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited administration site reactions | 53 Participants |
| Cohort 4: Placebo | Number of Participants With Solicited Administration Site and Systemic Reactions | Solicited systemic reactions | 51 Participants |
Primary
Number of Participants With Unsolicited Adverse Events
An AE is any untoward medical occurrence in a participant or in a clinical investigation participant administered a medicinal product and which does not necessarily have a causal relationship with this treatment. An unsolicited AE is an observed AE that does not fulfill the conditions pre-listed in the CRB in terms of diagnosis and/or onset window post-vaccination.
Time frame: Cohorts 1 and 3: Within 28 days after vaccination on Day 0; Cohorts 2 and 4: Within 28 days after vaccination on Days 0 and 56
Population: The SafAS included participants who received at least 1 administration of the study vaccine.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Cohort 1: RSV Low Dose | Number of Participants With Unsolicited Adverse Events | 6 Participants |
| Cohort 1: Placebo | Number of Participants With Unsolicited Adverse Events | 2 Participants |
| Cohort 2: RSV Low Dose | Number of Participants With Unsolicited Adverse Events | 2 Participants |
| Cohort 2: Placebo | Number of Participants With Unsolicited Adverse Events | 5 Participants |
| Cohort 3: RSV High Dose | Number of Participants With Unsolicited Adverse Events | 0 Participants |
| Cohort 3: Placebo | Number of Participants With Unsolicited Adverse Events | 2 Participants |
| Cohort 4: RSV Low Dose | Number of Participants With Unsolicited Adverse Events | 43 Participants |
| Cohort 4: RSV High Dose | Number of Participants With Unsolicited Adverse Events | 35 Participants |
| Cohort 4: Placebo | Number of Participants With Unsolicited Adverse Events | 46 Participants |
Secondary
Geometric Mean Titers Against RSV A Neutralizing Antibody After the RSV Surveillance Season
RSV A neutralizing antibody measured by microneutralization. RSV-naïve and RSV-experienced participants are defined as undetectable or detectable serum anti-RSV A IgA antibodies, respectively.
Time frame: Cohorts 1 and 3: Within 5 months after vaccination on Day 0; Cohorts 2 and 4: Within 5 months after vaccination on Day 56
Population: The FAS included all randomized participants who received at least 1 administration of the study vaccine. Only participants analyzed for this outcome measure are reported.
| Arm | Measure | Value (GEOMETRIC_MEAN) |
|---|---|---|
| Cohort 1: RSV Low Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody After the RSV Surveillance Season | 73.2 titer |
| Cohort 1: Placebo | Geometric Mean Titers Against RSV A Neutralizing Antibody After the RSV Surveillance Season | 24.4 titer |
| Cohort 2: RSV Low Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody After the RSV Surveillance Season | 303 titer |
| Cohort 2: Placebo | Geometric Mean Titers Against RSV A Neutralizing Antibody After the RSV Surveillance Season | 16.6 titer |
| Cohort 3: RSV High Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody After the RSV Surveillance Season | 294 titer |
| Cohort 3: Placebo | Geometric Mean Titers Against RSV A Neutralizing Antibody After the RSV Surveillance Season | 108 titer |
| Cohort 4: RSV Low Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody After the RSV Surveillance Season | 112 titer |
| Cohort 4: RSV High Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody After the RSV Surveillance Season | 123 titer |
| Cohort 4: Placebo | Geometric Mean Titers Against RSV A Neutralizing Antibody After the RSV Surveillance Season | 56.6 titer |
Secondary
Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Experienced Participants
RSV A neutralizing antibody measured by microneutralization. RSV-experienced participants are defined as detectable serum anti-RSV A IgA antibodies. CI= confidence interval.
Time frame: Cohorts 1 and 3: Day 56; Cohorts 2 and 4: Days 56 and 84
Population: The FAS included all randomized participants who received at least 1 administration of the study vaccine. Only participants analyzed at each specific time point are reported.
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| Cohort 1: RSV Low Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Experienced Participants | Day 56 | 134 titer |
| Cohort 1: Placebo | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Experienced Participants | Day 56 | 52.1 titer |
| Cohort 2: RSV Low Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Experienced Participants | Day 84 | 243 titer |
| Cohort 2: RSV Low Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Experienced Participants | Day 56 | 672 titer |
| Cohort 3: RSV High Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Experienced Participants | Day 56 | 409 titer |
| Cohort 3: Placebo | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Experienced Participants | Day 56 | 15.0 titer |
| Cohort 4: RSV Low Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Experienced Participants | Day 56 | 120 titer |
| Cohort 4: RSV Low Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Experienced Participants | Day 84 | 120 titer |
| Cohort 4: RSV High Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Experienced Participants | Day 56 | 96.0 titer |
| Cohort 4: RSV High Dose | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Experienced Participants | Day 84 | 102 titer |
| Cohort 4: Placebo | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Experienced Participants | Day 84 | 96.7 titer |
| Cohort 4: Placebo | Geometric Mean Titers Against RSV A Neutralizing Antibody in RSV-Experienced Participants | Day 56 | 73.5 titer |
Secondary
Geometric Mean Titers Against Serum Anti-F Immunoglobulin G Antibody After the RSV Surveillance Season
The IgG antibodies to RSV F antigen was measured using the anti RSV F IgG ELISA. RSV-naïve and RSV-experienced participants are defined as undetectable or detectable serum anti-RSV A IgA antibodies, respectively.
Time frame: Cohorts 1 and 3: Within 5 months after vaccination on Day 0; Cohorts 2 and 4: Within 5 months after vaccination on Day 56
Population: The FAS included all randomized participants who received at least 1 administration of the study vaccine. Only participants analyzed for this outcome measure are reported.
| Arm | Measure | Value (GEOMETRIC_MEAN) |
|---|---|---|
| Cohort 1: RSV Low Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G Antibody After the RSV Surveillance Season | 63.7 titer |
| Cohort 1: Placebo | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G Antibody After the RSV Surveillance Season | 14.2 titer |
| Cohort 2: RSV Low Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G Antibody After the RSV Surveillance Season | 388 titer |
| Cohort 2: Placebo | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G Antibody After the RSV Surveillance Season | 8.63 titer |
| Cohort 3: RSV High Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G Antibody After the RSV Surveillance Season | 296 titer |
| Cohort 3: Placebo | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G Antibody After the RSV Surveillance Season | 272 titer |
| Cohort 4: RSV Low Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G Antibody After the RSV Surveillance Season | 222 titer |
| Cohort 4: RSV High Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G Antibody After the RSV Surveillance Season | 300 titer |
| Cohort 4: Placebo | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G Antibody After the RSV Surveillance Season | 94.4 titer |
Secondary
Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody
The IgG antibodies to RSV F antigen was measured using the anti RSV F IgG ELISA. RSV-naïve and RSV-experienced participants are defined as undetectable or detectable serum anti-RSV A IgA antibodies, respectively.
Time frame: Cohorts 1 and 3: Day 56; Cohorts 2 and 4: Days 56 and 84
Population: The FAS included all randomized participants who received at least 1 administration of the study vaccine. Only participants analyzed at each specific time point are reported.
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| Cohort 1: RSV Low Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-naïve participants: Day 56 | 32.8 titer |
| Cohort 1: RSV Low Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-experienced participants: Day 56 | 205 titer |
| Cohort 1: Placebo | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-naïve participants: Day 56 | 15.0 titer |
| Cohort 1: Placebo | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-experienced participants: Day 56 | 38.5 titer |
| Cohort 2: RSV Low Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-naïve participants: Day 84 | 135 titer |
| Cohort 2: RSV Low Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-experienced participants: Day 84 | 165 titer |
| Cohort 2: RSV Low Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-naïve participants: Day 56 | 58.8 titer |
| Cohort 2: RSV Low Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-experienced participants: Day 56 | 230 titer |
| Cohort 2: Placebo | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-naïve participants: Day 56 | 8.63 titer |
| Cohort 2: Placebo | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-naïve participants: Day 84 | 8.72 titer |
| Cohort 3: RSV High Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-naïve participants: Day 56 | 48.7 titer |
| Cohort 3: RSV High Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-experienced participants: Day 56 | 337 titer |
| Cohort 3: Placebo | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-naïve participants: Day 56 | 7.50 titer |
| Cohort 3: Placebo | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-experienced participants: Day 56 | 7.50 titer |
| Cohort 4: RSV Low Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-experienced participants: Day 56 | 215 titer |
| Cohort 4: RSV Low Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-naïve participants: Day 56 | 43.2 titer |
| Cohort 4: RSV Low Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-naïve participants: Day 84 | 93.1 titer |
| Cohort 4: RSV Low Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-experienced participants: Day 84 | 250 titer |
| Cohort 4: RSV High Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-naïve participants: Day 56 | 45.6 titer |
| Cohort 4: RSV High Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-naïve participants: Day 84 | 61.8 titer |
| Cohort 4: RSV High Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-experienced participants: Day 84 | 287 titer |
| Cohort 4: RSV High Dose | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-experienced participants: Day 56 | 251 titer |
| Cohort 4: Placebo | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-experienced participants: Day 84 | 221 titer |
| Cohort 4: Placebo | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-naïve participants: Day 56 | 10.4 titer |
| Cohort 4: Placebo | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-naïve participants: Day 84 | 12.5 titer |
| Cohort 4: Placebo | Geometric Mean Titers Against Serum Anti-F Immunoglobulin G (IgG) Antibody | RSV-experienced participants: Day 56 | 124 titer |
Secondary
Percentage of Participants Infected With Vaccine Virus at Days 56 and 84
Infection is defined as detection of vaccine virus in nasal swab by RT-PCR and/or a \>= 4-fold rise in RSV A serum neutralizing antibody titers, or in RSV serum anti-F immunoglobulin G (IgG) antibody titers.
Time frame: Cohorts 1 and 3: Day 56; Cohorts 2 and 4: Days 56 and 84
Population: The FAS included all randomized participants who received at least 1 administration of the study vaccine. Only participants analyzed at each specific time point are reported.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Cohort 1: RSV Low Dose | Percentage of Participants Infected With Vaccine Virus at Days 56 and 84 | After first vaccination | 82.4 percentage of participants |
| Cohort 1: Placebo | Percentage of Participants Infected With Vaccine Virus at Days 56 and 84 | After first vaccination | 12.5 percentage of participants |
| Cohort 2: RSV Low Dose | Percentage of Participants Infected With Vaccine Virus at Days 56 and 84 | After first vaccination | 100 percentage of participants |
| Cohort 2: RSV Low Dose | Percentage of Participants Infected With Vaccine Virus at Days 56 and 84 | After second vaccination | 71.4 percentage of participants |
| Cohort 2: Placebo | Percentage of Participants Infected With Vaccine Virus at Days 56 and 84 | After second vaccination | 0 percentage of participants |
| Cohort 2: Placebo | Percentage of Participants Infected With Vaccine Virus at Days 56 and 84 | After first vaccination | 0 percentage of participants |
| Cohort 3: RSV High Dose | Percentage of Participants Infected With Vaccine Virus at Days 56 and 84 | After first vaccination | 100 percentage of participants |
| Cohort 3: Placebo | Percentage of Participants Infected With Vaccine Virus at Days 56 and 84 | After first vaccination | 0 percentage of participants |
| Cohort 4: RSV Low Dose | Percentage of Participants Infected With Vaccine Virus at Days 56 and 84 | After second vaccination | 64.1 percentage of participants |
| Cohort 4: RSV Low Dose | Percentage of Participants Infected With Vaccine Virus at Days 56 and 84 | After first vaccination | 63.3 percentage of participants |
| Cohort 4: RSV High Dose | Percentage of Participants Infected With Vaccine Virus at Days 56 and 84 | After first vaccination | 58.3 percentage of participants |
| Cohort 4: RSV High Dose | Percentage of Participants Infected With Vaccine Virus at Days 56 and 84 | After second vaccination | 51.2 percentage of participants |
| Cohort 4: Placebo | Percentage of Participants Infected With Vaccine Virus at Days 56 and 84 | After first vaccination | 4.0 percentage of participants |
| Cohort 4: Placebo | Percentage of Participants Infected With Vaccine Virus at Days 56 and 84 | After second vaccination | 18.8 percentage of participants |
Secondary
Titer of Vaccine Virus Shedding Measured by Reverse Transcription Polymerase Chain Reaction (RT-PCR)
Shedding of the attenuated RSV vaccine strain in nasal swab samples was evaluated by RSV quantitative RT-PCR (qRT-PCR) assay, which specifically detected and quantified RSVt ΔNS2 vaccine strain (RSV ΔNS2/Δ1313/I1314L) in human nasal swab samples.
Time frame: Cohorts 1 and 3: Day 7; Cohorts 2 and 4: Days 7 and 63
Population: The SafAS included participants who received at least 1 administration of the study vaccine.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cohort 1: RSV Low Dose | Titer of Vaccine Virus Shedding Measured by Reverse Transcription Polymerase Chain Reaction (RT-PCR) | After first vaccination | 5.02 log10 copies/mL | Standard Deviation 1.03 |
| Cohort 2: RSV Low Dose | Titer of Vaccine Virus Shedding Measured by Reverse Transcription Polymerase Chain Reaction (RT-PCR) | After first vaccination | 6.27 log10 copies/mL | Standard Deviation 0.883 |
| Cohort 2: RSV Low Dose | Titer of Vaccine Virus Shedding Measured by Reverse Transcription Polymerase Chain Reaction (RT-PCR) | After second vaccination | 5.35 log10 copies/mL | — |
| Cohort 3: RSV High Dose | Titer of Vaccine Virus Shedding Measured by Reverse Transcription Polymerase Chain Reaction (RT-PCR) | After first vaccination | 5.82 log10 copies/mL | Standard Deviation 0.666 |
| Cohort 4: RSV Low Dose | Titer of Vaccine Virus Shedding Measured by Reverse Transcription Polymerase Chain Reaction (RT-PCR) | After second vaccination | 5.10 log10 copies/mL | Standard Deviation 1.78 |
| Cohort 4: RSV Low Dose | Titer of Vaccine Virus Shedding Measured by Reverse Transcription Polymerase Chain Reaction (RT-PCR) | After first vaccination | 5.16 log10 copies/mL | Standard Deviation 0.94 |
| Cohort 4: RSV High Dose | Titer of Vaccine Virus Shedding Measured by Reverse Transcription Polymerase Chain Reaction (RT-PCR) | After second vaccination | 5.76 log10 copies/mL | Standard Deviation 1.21 |
| Cohort 4: RSV High Dose | Titer of Vaccine Virus Shedding Measured by Reverse Transcription Polymerase Chain Reaction (RT-PCR) | After first vaccination | 5.21 log10 copies/mL | Standard Deviation 0.985 |