Randomized Phase I/II Study of the Safety and Immunogenicity of a Single Dose of the Recombinant Live-Attenuated Respiratory Syncytial Virus (RSV) Vaccines RSV ΔNS2/Δ1313/I1314L, RSV 6120/ΔNS2/1030s, RSV 276 or Placebo, Delivered as Nose Drops to RSV-Seronegative Children 6 to 24 Months of Age
Overview
- Phase
- Phase 1
- Intervention
- RSV ΔNS2/Δ1313/I1314L Vaccine
- Conditions
- Respiratory Syncytial Virus (RSV)
- Sponsor
- National Institute of Allergy and Infectious Diseases (NIAID)
- Enrollment
- 67
- Locations
- 14
- Primary Endpoint
- Percentage With Grade 1 or Higher Solicited Adverse Events (AEs)
- Status
- Terminated
- Last Updated
- last year
Overview
Brief Summary
The purpose of this study was to evaluate the safety and immunogenicity of a single dose of the recombinant live-attenuated respiratory syncytial virus (RSV) vaccines, RSV ΔNS2/Δ1313/I1314L, RSV 6120/ΔNS2/1030s, and RSV 276, in RSV-seronegative children 6 to 24 months of age.
Detailed Description
This study evaluated the safety and immunogenicity of a single dose of the recombinant live-attenuated respiratory syncytial virus (RSV) vaccines, RSV ΔNS2/Δ1313/I1314L, RSV 6120/ΔNS2/1030s, and RSV 276, in RSV-seronegative children 6 to 24 months of age. Participants were randomly assigned to receive a single dose of RSV ΔNS2/Δ1313/I1314L vaccine, RSV 6120/ΔNS2/1030s vaccine, RSV 276 vaccine, or placebo intranasally at study entry. Participants were enrolled in the study outside of RSV season. All participants were to remain on study until they completed the post-RSV season visit in the calendar year following enrollment. Participants' total study duration was expected to be between 5 and 15 months, depending on when they enrolled in the study and accommodations given for the COVID pandemic. Participants attended several study visits throughout the study, which included physical examinations, blood collection, and nasal washes or swabs, if applicable. Participants' parents or guardians were contacted by study staff at various times during the study to monitor participants' health. The study closed to enrollment prior to fully accruing due to difficulties with slower than expected accrual.
Investigators
Eligibility Criteria
Inclusion Criteria
- •In good health based on review of the medical record, history, and physical examination, without evidence of chronic disease.
- •Parent/guardian is willing and able to provide written informed consent as described in the study protocol.
- •Seronegative for RSV antibody, defined as a serum RSV-neutralizing antibody titer less than 1:40 at screening from a sample collected no more than 42 days prior to study product administration.
- •Note: results from specimens collected during screening for any study of an RSV vaccine developed by the Laboratory of Infectious Diseases (LID) (National Institute of Allergy and Infectious Diseases \[NIAID\], National Institutes of Health \[NIH\]) are acceptable. If study product will not be administered the same day as randomization (see the study protocol), it must be administered no more than 42 days after the screening sample is collected.
- •Growing normally for age in the opinion of the site clinician in the six months prior to enrollment AND has a current height and weight above the 3rd percentile for age and sex per Centers for Disease Control and Prevention (CDC) World Health Organization (WHO) growth standards.
- •Has received routine immunizations appropriate for age (as per national Center for Disease Control Advisory Committee on Immunization Practices \[ACIP\]). Note: COVID-19 vaccination will not be required unless fully licensed for this age group and ACIP-recommended. See study-specific Manual of Procedures for further guidance
- •Is expected to be available for the duration of the study.
- •If born to an HIV-infected woman, potential participant must have documentation of 2 negative HIV nucleic acid (RNA or DNA) test results from samples collected on different dates with both collected when greater than or equal to 4 weeks of age and at least one collected when greater than or equal to 16 weeks of age, and no positive HIV nucleic acid (RNA or DNA) test; or 2 negative HIV antibody tests, both from samples collected at greater than or equal to 24 weeks of age. If potential participant was breastfed by an HIV-infected woman, each of the sampling times noted above must be measured in weeks after the last exposure to breast milk, rather than weeks of age.
Exclusion Criteria
- •Prior laboratory-confirmed RSV infection.
- •Known or suspected HIV infection or impairment of immunological functions.
- •Receipt of immunosuppressive therapy, including any systemic, nasal, or inhaled corticosteroids within 28 days of enrollment. Note: Cutaneous (topical) steroid treatment is not an exclusion.
- •Any receipt of bone marrow/solid organ transplant.
- •Major congenital malformations (such as congenital cleft palate) or cytogenetic abnormalities.
- •Previous enrollment in this trial, previous pediatric receipt of a licensed or investigational RSV vaccine, or previous maternal or pediatric receipt of or planned administration of any other anti-RSV product (such as ribavirin or RSV IG or RSV monoclonal antibody \[mAb\]) within 4 months of screening or planned administration of an anti-RSV product between screening and day 56 after enrollment.
- •Any previous anaphylactic reaction.
- •Any known hypersensitivity to any study product component.
- •Heart disease. Note: Potential participants with cardiac abnormalities documented to be clinically insignificant and requiring no treatment may be enrolled.
- •Lung disease, including any history of reactive airway disease or medically diagnosed wheezing.
Arms & Interventions
RSV ΔNS2/Δ1313/I1314L Vaccine
Participants received a single dose of the RSV ΔNS2/Δ1313/I1314L vaccine at study entry (Day 0).
Intervention: RSV ΔNS2/Δ1313/I1314L Vaccine
RSV 6120/ΔNS2/1030s Vaccine
Participants received a single dose of the RSV 6120/ΔNS2/1030s vaccine at study entry (Day 0).
Intervention: RSV 6120/ΔNS2/1030s Vaccine
RSV 276 Vaccine
Participants received a single dose of the RSV 276 vaccine at study entry (Day 0).
Intervention: RSV 276 Vaccine
Placebo
Participants received a single dose of placebo at study entry (Day 0).
Intervention: Placebo
Outcomes
Primary Outcomes
Percentage With Grade 1 or Higher Solicited Adverse Events (AEs)
Time Frame: Day 0 through Day 28
Solicited adverse events include fever, otitis media, upper respiratory illness (URI), and lower respiratory illness (LRI) and are graded following a protocol-defined grading system. Adverse events were graded on a scale from 1-5: 1=mild, 2=moderate, 3=severe, 4=life-threatening, 5=death. All solicited AEs with at least mild severity were included. Percentage with 95% exact confidence intervals using the Clopper-Pearson method were calculated.
Percentage With Grade 2 or Higher Lower Respiratory Illnesses (LRIs)
Time Frame: Day 0 through Day 28
LRIs graded following a protocol-defined grading system. Adverse events were graded on a scale from 1-5: 1=mild, 2=moderate, 3=severe, 4=life-threatening, 5=death. All solicited LRIs with at least moderate severity were included. Percentage with 95% exact confidence intervals using the Clopper-Pearson method were calculated.
Percentage With Serious AEs
Time Frame: Day 0 through Day 56
Serious adverse events are defined according to Version 2.0 of the DAIDS EAE Manual. A serious event is one that requires or lengthens hospitalization, that is life-threatening, that results in death, that results in a significant disability, or that is a congenital anomaly or birth defect. Percentage with 95% exact confidence intervals using the Clopper-Pearson method were calculated.
Percentage With a Greater Than or Equal to 4-fold Rise in Serum RSV-neutralizing Antibody Titer
Time Frame: Measured at pre-study product administration (screening) through Day 56
Antibody responses were defined as a greater than or equal to 4-fold increase in titer in paired specimens, between pre-study product administration and Day 56 time points. Percentage with 95% exact confidence intervals (CIs) using the Clopper-Pearson method were calculated. The upper limit of the CI was compared to an a priori limit of 70%. An upper limit above 70% was considered a good vaccine candidate.
Secondary Outcomes
- Percentage With a Greater Than or Equal to 4-fold Rise in Serum RSV F Immunoglobulin G (IgG)(Measured at pre-study product administration (screening) and Day 56)
- Titer of Serum RSV-neutralizing Antibodies(Measured at the Day 56 Visit)
- Titer of Serum RSV F IgG(Measured at the Day 56 Visit)
- Maximum Grade (if More Than One Illness Within a Participant) of RSV-MAARI(Measured through the last day of the RSV season, which will occur between 5 and 15 months after study entry, depending on when the participant enrolls in the study)
- Percentage With RSV-associated Medically Attended Acute Respiratory Illness (RSV-MAARI)(Measured through the last day of the RSV season, which will occur between 5 and 15 months after study entry, depending on when the participant enrolls in the study)
- Percentage With RSV-associated Medically Attended Acute Lower Respiratory Illness (RSV-MAALRI)(Measured through the last day of the RSV season, which will occur between 5 and 15 months after study entry, depending on when the participant enrolls in the study)
- Maximum Grade (if More Than One Illness Within a Participant) of RSV-MAALRI(Measured through the last day of the RSV season, which will occur between 5 and 15 months after study entry, depending on when the participant enrolls in the study)