Chikungunya Virus
Conditions
Keywords
Chikungunya, VLP, PXVX0317, vaccine, immunogenicity, CHIKV
Brief summary
The goal of this multi-center, randomized, double blind, placebo controlled study is to evaluate the safety and immunogenicity of PXVX0317 (CHIKV VLP vaccine) in healthy adult and adolescent subjects.
Detailed description
Coprimary Objectives: 1. To evaluate the safety of PXVX0317 (CHIKV VLP vaccine) in healthy adult and adolescent participants 12 to \<65 years of age. 2. To compare the anti-CHIKV serum neutralizing antibody (SNA) response to PXVX0317 (CHIKV VLP vaccine) and placebo at Day 22, as measured by geometric mean titer (GMT) and clinically relevant difference in seroresponse rate (PXVX0317 minus placebo). 3. To demonstrate the consistency of the anti-CHIKV SNA response across three consecutively manufactured lots of PXVX0317 (CHIKV VLP vaccine) at Day 22 as measured by GMT. Secondary Objectives: 1. To compare the anti-CHIKV SNA response to PXVX0317 (CHIKV VLP vaccine) and placebo at Day 15, Day 183, and Day 8 as measured by GMT and seroresponse rate. 2. To compare the GMT fold increase in anti-CHIKV SNA response and number and percentage of participants with an anti-CHIKV SNA titer ≥15 and 4-fold rise over baseline, both at Day 8, 15, 22, and 183.
Interventions
BIOLOGICALCHIKV VLP/adjuvant
CHIKV VLP vaccine is comprised of chikungunya virus virus-like particles (CHIKV VLP), adsorbed on aluminum hydroxide adjuvant 2%
BIOLOGICALPlacebo
Placebo is comprised of formulation buffer
Sponsors
Emergent BioSolutions
Bavarian Nordic
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Caregiver, Investigator)
Intervention model description
Participants will be randomized in a 2:2:2:1 ratio within each age stratum (12 to \<18, 18 to \<46, and 46 to \<65). This study will be conducted in the US, using up to 50 sites.
Eligibility
Sex/Gender
ALL
Age
12 Years to 64 Years
Healthy volunteers
Yes
Inclusion criteria
* Able and willing to provide informed consent (and assent, as applicable) voluntarily signed by participant (and guardian, as applicable). * Males or females, 12 to \<65 years of age. * Generally healthy, in the opinion of the investigator, based on medical history, physical examination, and screening laboratory assessments. * Women who are either: (i) Not of childbearing potential (CBP): pre-menarche, surgically sterile (at least six weeks post bilateral tubal ligation, bilateral oophorectomy or hysterectomy), or postmenopausal (defined as a history of ≥12 consecutive months without menses prior to randomization in the absence of other pathologic or physiologic causes, following cessation of exogenous sex-hormonal treatment) or (ii) Meeting all the below criteria: Negative serum pregnancy test at screening visit, Negative urine pregnancy test immediately prior to dosing at Day 1, Using an acceptable method of contraception (if women of CBP) for the duration of participation, such as hormonal contraceptives (eg, implants, pills, patches) initiated ≥30 days prior to dosing, intrauterine device (IUD) inserted ≥30 days prior to dosing, double barrier type of birth control (male condom with female diaphragm, male condom with cervical cap), Abstinence is acceptable only for adolescents (12 to \<18 years old) who are not sexually active.
Exclusion criteria
* Currently pregnant, breastfeeding, or planning to become pregnant during the study. * Body Mass Index (BMI) ≥35 kg/m2. * Positive laboratory evidence of current infection with human immunodeficiency virus (HIV-1, HIV-2), hepatitis C virus (HCV) or hepatitis B virus (HBV). * History of severe allergic reaction or anaphylaxis to any component of the vaccine. * History of any known congenital or acquired immunodeficiency that could impact response to vaccination (eg, leukemia, lymphoma, generalized malignancy, functional or anatomic asplenia, alcoholic cirrhosis). * Prior receipt or anticipated use of systemic immunomodulatory or immunosuppressive medications from six months prior to screening through Day 22. Note: For systemic corticosteroids, use at a dose or equivalent dose of 20 mg of prednisone daily for 14 days or more within three months of screening through Day 22 is exclusionary. The use of inhaled, intranasal, topical, ocular, or intraocular steroids is allowed. * Receipt or anticipated receipt of blood or blood-derived products from 90 days prior to screening through Day 22. * Acute disease within the last 14 days (participants with an acute mild febrile illness can be considered for a deferral of vaccination two weeks after the illness has resolved and treatment has been completed). * Clinically significant cardiac, pulmonary, rheumatologic, or other chronic disease, in the opinion of the investigator. This may include chronic illness requiring hospitalization in the last 30 days prior to screening. * Enrollment in an interventional study and/or receipt of another investigational product from 30 days prior to screening through the duration of study participation. * Receipt or anticipated receipt of any vaccine from 30 days prior to Day 1 through Day 22. * Evidence of substance abuse that, in the opinion of the investigator, could adversely impact the participant's participation or the conduct of the study. * Prior receipt of an investigational CHIKV vaccine/product. * Any other medical condition that, in the opinion of the investigator, could adversely impact the participant's participation or the conduct of the study.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 (Data Reported Per Arm - Adults 18 to <46) | 21 days post-vaccination | Anti-CHIKV SNA GMTs and associated 95% CIs for PXVX0317 (CHIKV VLP vaccine) and placebo in adults 18 to \<46 years of age in the IEP at Day 22. |
| Incidence of Solicited Adverse Events (AE) | 7 days post-vaccination | Incidence of solicited AEs through Day 8 for PXVX0317 (CHIKV VLP vaccine) and placebo for all age strata combined (safety population). |
| Incidence of Unsolicited AEs | 28 days post-vaccination | Incidence of unsolicited AEs through Day 29 for PXVX0317 (CHIKV VLP vaccine) and placebo for all age strata combined (safety population). |
| Incidence of Adverse Events of Special Interest (AESI) | 182 days post-vaccination | Incidence of AESIs, through Day 183 for PXVX0317 (CHIKV VLP vaccine) and placebo for all age strata combined (safety population). |
| Anti-CHIKV Serum Neutralizing Antibody (SNA) Seroresponse Rates at Day 22 | 21 days post-vaccination | Anti-CHIKV SNA seroresponse rates for PXVX0317 (CHIKV VLP vaccine) and placebo, difference (PXVX0317 minus placebo), and associated 95% confidence interval (CI) at Day 22 for the immunogenicity evaluable population (IEP), all age strata combined. |
| Anti-CHIKV Serum Neutralizing Antibody (SNA) Seroresponse Rates at Day 22 (Data Reported Per Arm) | 21 days post-vaccination | Anti-CHIKV SNA seroresponse rates and associated 95% confidence interval for PXVX0317 (CHIKV VLP vaccine) and placebo at Day 22 for the immunogenicity evaluable population (IEP), all age strata combined. |
| Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 | 21 days post-vaccination | Anti-CHIKV SNA GMTs and associated 95% CIs at Day 22 for PXVX0317 (CHIKV VLP vaccine) and placebo for the IEP, all age strata combined. |
| Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 (Data Reported Per Arm - All Age Strata) | 21 days post-vaccination | Anti-CHIKV SNA GMTs and associated 95% CIs at Day 22 for PXVX0317 (CHIKV VLP vaccine) and placebo for the IEP, all age strata combined. |
| Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 (for Lot Comparison) | 21 days post-vaccination | Anti-CHIKV SNA GMTs and associated 95% CIs between all three pairs of PXVX0317 (CHIKV VLP vaccine) lots (104:105, 104:106, 105:106) in adults 18 to \<46 years of age in the IEP at Day 22. Placebo group 4 is not relevant for this lot-to-lot consistency analysis. Reported GMT estimates and 95% CIs are derived from an ANOVA model that includes site and product lot as fixed effects assuming normality of log titers. |
| Incidence of Serious Adverse Event (SAE) | 182 days post-vaccination | Incidence of SAEs through Day 183 for PXVX0317 (CHIKV VLP vaccine) and placebo for all age strata combined (safety population). |
| Incidence of Medically Attended Adverse Event (MAAE) | 182 days post-vaccination | Incidence of MAAEs through Day 183 for PXVX0317 (CHIKV VLP vaccine) and placebo for all age strata combined (safety population). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 (Data Reported Per Arm) | Day 15, 183, and 8 (14, 182, and 7 days post-vaccination, respectively) | Anti-CHIKV SNA seroresponse rates and associated 95% CIs for PXVX0317 (CHIKV VLP vaccine) and placebo at Day 15, Day 183, and Day 8, in that order, for the IEP, all age strata combined. Number analyzed is number of participants with a sample result available at the indicated visit. |
| Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 | Day 8, 15, and 183 (7, 14, and 182 days post-vaccination, respectively) | Anti-CHIKV SNA GMTs with associated 95% CIs at Day 8, Day 15, and Day 183 for PXVX0317 (CHIKV VLP vaccine) and placebo for the IEP, all age strata combined. Number analyzed is number of participants with a sample result available at the indicated visit. |
| Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 (Data Reported Per Arm) | Day 8, 15, and 183 (7, 14, and 182 days post-vaccination, respectively) | Anti-CHIKV SNA GMTs with associated 95% CIs at Day 8, Day 15, and Day 183 for PXVX0317 (CHIKV VLP vaccine) and placebo for the IEP, all age strata combined. Number analyzed is number of participants with a sample result available at the indicated visit |
| Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 | Day 8, 15, 22, and 183 (7,14, 21, and 182 days post-vaccination, respectively) | Geometric mean fold increase (GMFI) in anti-CHIKV SNA titers from Day 1 to Day 8, Day 15, Day 22, and Day 183 for the IEP for all age strata combined. Fold rise in geometric mean titer is the ratio of the post-baseline value to the baseline value (e.g. number of 2 represents a post-baseline doubling of geometric mean titer). Number analyzed is number of participants with a sample result available at both Day 1 and the indicated visit. |
| Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 (Data Reported Per Arm) | Day 8, 15, 22, and 183 (7,14, 21, and 182 days post-vaccination, respectively) | Geometric mean fold increase (GMFI) in anti-CHIKV SNA titers from Day 1 to Day 8, Day 15, Day 22, and Day 183 for the IEP for all age strata combined. Fold rise in geometric mean titer is the ratio of the post-baseline value to the baseline value (e.g. number of 2 represents a post-baseline doubling of geometric mean titer). Number analyzed is number of participants with a sample result available at both Day 1 and the indicated visit. |
| Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | Day 8, 15, 22, and 183 (7,14, 21, and 182 days post-vaccination, respectively) | Number and percentage of participants with anti-CHIKV SNA titers ≥15 and 4-fold rise over baseline at Day 8, Day 15, Day 22, and Day 183 for the IEP for all age strata combined. Number analyzed is number of participants with a sample result available at the indicated visit. |
| Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | Day 8, 15, 22, and 183 (7,14, 21, and 182 days post-vaccination, respectively) | Number and percentage of participants with anti-CHIKV SNA titers ≥15 and 4-fold rise over baseline at Day 8, Day 15, Day 22, and Day 183 for the IEP for all age strata combined. Number analyzed is number of participants with a sample result available at the indicated visit. |
| Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 | Day 15, 183, and 8 (14, 182, and 7 days post-vaccination, respectively) | Anti-CHIKV SNA seroresponse rates for PXVX0317 (CHIKV VLP vaccine) and placebo, difference (PXVX0317 minus placebo), and associated 95% CIs at Day 15, Day 183, and Day 8, in that order, for the IEP, all age strata combined. Number analyzed is number of participants with a sample result available at the indicated visit. |
Countries
United States
Participant flow
Recruitment details
This was a multicenter study conducted in the United States, using 47 sites. Healthy participants were enrolled in this study. Recruitment Period was from September 29, 2021 to October 06, 2022.
Participants by arm
| Arm | Count |
|---|---|
| Group 1 Group 1 - PXVX0317 lot 104
CHIKV VLP/adjuvant: CHIKV VLP vaccine is comprised of chikungunya virus virus-like particles (CHIKV VLP), adsorbed on aluminum hydroxide adjuvant 2% | 919 |
| Group 2 Group 2 - PXVX0317 lot 105
CHIKV VLP/adjuvant: CHIKV VLP vaccine is comprised of chikungunya virus virus-like particles (CHIKV VLP), adsorbed on aluminum hydroxide adjuvant 2% | 948 |
| Group 3 Group 3 - PXVX0317 lot 106
CHIKV VLP/adjuvant: CHIKV VLP vaccine is comprised of chikungunya virus virus-like particles (CHIKV VLP), adsorbed on aluminum hydroxide adjuvant 2% | 927 |
| Group 4 Group 4 - Placebo
Placebo: Placebo is comprised of formulation buffer | 464 |
| Total | 3,258 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 | FG003 |
|---|---|---|---|---|---|
| Overall Study | Death | 0 | 0 | 1 | 0 |
| Overall Study | Lost to Follow-up | 65 | 70 | 58 | 23 |
| Overall Study | Noncompliance (protocol, study, visits, e-diary, etc.) | 0 | 2 | 1 | 1 |
| Overall Study | Physician Decision | 2 | 1 | 1 | 0 |
| Overall Study | Sponsor Decision | 0 | 1 | 0 | 0 |
| Overall Study | Subject incarcerated | 0 | 1 | 0 | 1 |
| Overall Study | Subject left site without receiving dose | 0 | 1 | 0 | 0 |
| Overall Study | Subject missed last visit (Day 183) | 3 | 1 | 1 | 0 |
| Overall Study | Subject moved | 1 | 3 | 5 | 2 |
| Overall Study | Subject was deployed | 0 | 1 | 0 | 0 |
| Overall Study | Withdrawal by parent | 0 | 0 | 1 | 0 |
| Overall Study | Withdrawal by Subject | 45 | 30 | 27 | 7 |
Baseline characteristics
| Characteristic | Group 2 | Group 3 | Group 1 | Group 4 | Total |
|---|---|---|---|---|---|
| Age, Continuous | 38 years STANDARD_DEVIATION 14.3 | 39 years STANDARD_DEVIATION 14 | 39 years STANDARD_DEVIATION 14.4 | 39 years STANDARD_DEVIATION 14.4 | 39 years STANDARD_DEVIATION 14.3 |
| Baseline Anti-CHIKV SNA Serostatus Missing | 5 Participants | 0 Participants | 1 Participants | 0 Participants | 6 Participants |
| Baseline Anti-CHIKV SNA Serostatus Negative (<LLOQ) | 925 Participants | 906 Participants | 894 Participants | 458 Participants | 3183 Participants |
| Baseline Anti-CHIKV SNA Serostatus Positive (>=LLOQ) | 18 Participants | 21 Participants | 24 Participants | 6 Participants | 69 Participants |
| Body Mass Index (BMI) | 26.89 kg/m^2 STANDARD_DEVIATION 4.48 | 26.73 kg/m^2 STANDARD_DEVIATION 4.499 | 26.63 kg/m^2 STANDARD_DEVIATION 4.579 | 26.38 kg/m^2 STANDARD_DEVIATION 4.57 | 26.70 kg/m^2 STANDARD_DEVIATION 4.527 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 166 Participants | 175 Participants | 165 Participants | 71 Participants | 577 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 760 Participants | 731 Participants | 735 Participants | 379 Participants | 2605 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 22 Participants | 21 Participants | 19 Participants | 14 Participants | 76 Participants |
| Height | 170.4 cm STANDARD_DEVIATION 9.55 | 170.7 cm STANDARD_DEVIATION 10.02 | 171.4 cm STANDARD_DEVIATION 10.03 | 171.2 cm STANDARD_DEVIATION 9.97 | 170.9 cm STANDARD_DEVIATION 9.89 |
| Race (NIH/OMB) American Indian or Alaska Native | 6 Participants | 13 Participants | 11 Participants | 2 Participants | 32 Participants |
| Race (NIH/OMB) Asian | 30 Participants | 23 Participants | 26 Participants | 16 Participants | 95 Participants |
| Race (NIH/OMB) Black or African American | 175 Participants | 169 Participants | 190 Participants | 89 Participants | 623 Participants |
| Race (NIH/OMB) More than one race | 32 Participants | 23 Participants | 23 Participants | 8 Participants | 86 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 4 Participants | 0 Participants | 2 Participants | 4 Participants | 10 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 8 Participants | 12 Participants | 4 Participants | 4 Participants | 28 Participants |
| Race (NIH/OMB) White | 693 Participants | 687 Participants | 663 Participants | 341 Participants | 2384 Participants |
| Sex: Female, Male Female | 506 Participants | 478 Participants | 452 Participants | 231 Participants | 1667 Participants |
| Sex: Female, Male Male | 442 Participants | 449 Participants | 467 Participants | 233 Participants | 1591 Participants |
| Weight | 78.4 kg STANDARD_DEVIATION 16.08 | 78.3 kg STANDARD_DEVIATION 16.42 | 78.5 kg STANDARD_DEVIATION 16.5 | 77.6 kg STANDARD_DEVIATION 16.42 | 78.3 kg STANDARD_DEVIATION 16.34 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 918 | 0 / 945 | 1 / 927 | 0 / 464 |
| other Total, other adverse events | 323 / 918 | 375 / 945 | 367 / 927 | 127 / 464 |
| serious Total, serious adverse events | 10 / 918 | 7 / 945 | 6 / 927 | 1 / 464 |
Outcome results
Primary
Anti-CHIKV Serum Neutralizing Antibody (SNA) Seroresponse Rates at Day 22
Anti-CHIKV SNA seroresponse rates for PXVX0317 (CHIKV VLP vaccine) and placebo, difference (PXVX0317 minus placebo), and associated 95% confidence interval (CI) at Day 22 for the immunogenicity evaluable population (IEP), all age strata combined.
Time frame: 21 days post-vaccination
Population: Immunogenicity evaluable population (randomized and vaccinated participants who provided an evaluable Day 22 anti-CHIKV SNA sample within the analysis window, had no measurable anti-CHIKV SNA titer at Day 1, and had no reason to be excluded as defined prior to unblinding). Groups 1, 2, and 3 are combined, as participants received same treatment of PXVX0317 (dose, adjuvant, schedule), with only difference being the lot of manufactured vaccine. Data is reported for PXVX0317 vaccinated vs. placebo.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Group 1 | Anti-CHIKV Serum Neutralizing Antibody (SNA) Seroresponse Rates at Day 22 | 97.81 percentage of participants (rounded) |
| Group 2 | Anti-CHIKV Serum Neutralizing Antibody (SNA) Seroresponse Rates at Day 22 | 1.18 percentage of participants (rounded) |
Comparison: Day 22p-value: <0.000195% CI: [95, 97.5]Chi-squared
Primary
Anti-CHIKV Serum Neutralizing Antibody (SNA) Seroresponse Rates at Day 22 (Data Reported Per Arm)
Anti-CHIKV SNA seroresponse rates and associated 95% confidence interval for PXVX0317 (CHIKV VLP vaccine) and placebo at Day 22 for the immunogenicity evaluable population (IEP), all age strata combined.
Time frame: 21 days post-vaccination
Population: Immunogenicity evaluable population (randomized and vaccinated participants who provided an evaluable Day 22 anti-CHIKV SNA sample within the analysis window, had no measurable anti-CHIKV SNA titer at Day 1, and had no reason to be excluded as defined prior to unblinding).
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Group 1 | Anti-CHIKV Serum Neutralizing Antibody (SNA) Seroresponse Rates at Day 22 (Data Reported Per Arm) | 98.1 percentage of participants |
| Group 2 | Anti-CHIKV Serum Neutralizing Antibody (SNA) Seroresponse Rates at Day 22 (Data Reported Per Arm) | 98.0 percentage of participants |
| Group 3 | Anti-CHIKV Serum Neutralizing Antibody (SNA) Seroresponse Rates at Day 22 (Data Reported Per Arm) | 97.3 percentage of participants |
Primary
Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22
Anti-CHIKV SNA GMTs and associated 95% CIs at Day 22 for PXVX0317 (CHIKV VLP vaccine) and placebo for the IEP, all age strata combined.
Time frame: 21 days post-vaccination
Population: Immunogenicity evaluable population (randomized and vaccinated participants who provided an evaluable Day 22 anti-CHIKV SNA sample within the analysis window, had no measurable anti-CHIKV SNA titer at Day 1, and had no reason to be excluded as defined prior to unblinding). Groups 1, 2, and 3 are combined, as participants received same treatment of PXVX0317 (dose, adjuvant, schedule), with only difference being the lot of manufactured vaccine. Data is reported for PXVX0317 vaccinated vs. placebo.
| Arm | Measure | Value (GEOMETRIC_MEAN) |
|---|---|---|
| Group 1 | Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 | 1618 Titer |
| Group 2 | Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 | 8 Titer |
Comparison: Day 22p-value: <0.000195% CI: [183, 232]ANOVA
Primary
Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 (Data Reported Per Arm - Adults 18 to <46)
Anti-CHIKV SNA GMTs and associated 95% CIs for PXVX0317 (CHIKV VLP vaccine) and placebo in adults 18 to \<46 years of age in the IEP at Day 22.
Time frame: 21 days post-vaccination
Population: Adults 18 to \<46 years in Immunogenicity evaluable population (randomized and vaccinated participants who provided an evaluable Day 22 anti-CHIKV SNA sample within the analysis window, had no measurable anti-CHIKV SNA titer at Day 1, and had no reason to be excluded as defined prior to unblinding).
| Arm | Measure | Value (GEOMETRIC_MEAN) |
|---|---|---|
| Group 1 | Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 (Data Reported Per Arm - Adults 18 to <46) | 1838 Titer |
| Group 2 | Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 (Data Reported Per Arm - Adults 18 to <46) | 1866 Titer |
| Group 3 | Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 (Data Reported Per Arm - Adults 18 to <46) | 1932 Titer |
| Group 4 | Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 (Data Reported Per Arm - Adults 18 to <46) | 8 Titer |
Primary
Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 (Data Reported Per Arm - All Age Strata)
Anti-CHIKV SNA GMTs and associated 95% CIs at Day 22 for PXVX0317 (CHIKV VLP vaccine) and placebo for the IEP, all age strata combined.
Time frame: 21 days post-vaccination
Population: Immunogenicity evaluable population (randomized and vaccinated participants who provided an evaluable Day 22 anti-CHIKV SNA sample within the analysis window, had no measurable anti-CHIKV SNA titer at Day 1, and had no reason to be excluded as defined prior to unblinding).
| Arm | Measure | Value (GEOMETRIC_MEAN) |
|---|---|---|
| Group 1 | Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 (Data Reported Per Arm - All Age Strata) | 1592 Titer |
| Group 2 | Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 (Data Reported Per Arm - All Age Strata) | 1640 Titer |
| Group 3 | Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 (Data Reported Per Arm - All Age Strata) | 1622 Titer |
Primary
Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 (for Lot Comparison)
Anti-CHIKV SNA GMTs and associated 95% CIs between all three pairs of PXVX0317 (CHIKV VLP vaccine) lots (104:105, 104:106, 105:106) in adults 18 to \<46 years of age in the IEP at Day 22. Placebo group 4 is not relevant for this lot-to-lot consistency analysis. Reported GMT estimates and 95% CIs are derived from an ANOVA model that includes site and product lot as fixed effects assuming normality of log titers.
Time frame: 21 days post-vaccination
Population: Adults 18 to \<46 years in Immunogenicity evaluable population (randomized and vaccinated participants who provided an evaluable Day 22 anti-CHIKV SNA sample within the analysis window, had no measurable anti-CHIKV SNA titer at Day 1, and had no reason to be excluded as defined prior to unblinding). Placebo group 4 does not apply for this PXVX0317 lot-to-lot consistency analysis.
| Arm | Measure | Value (GEOMETRIC_MEAN) |
|---|---|---|
| Group 1 | Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 (for Lot Comparison) | 1857 titer |
| Group 2 | Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 (for Lot Comparison) | 1887 titer |
| Group 3 | Anti-CHIKV SNA Geometric Mean Titers (GMT) at Day 22 (for Lot Comparison) | 1950 titer |
95% CI: [0.85, 1.14]
95% CI: [0.84, 1.12]
95% CI: [0.82, 1.1]
Primary
Incidence of Adverse Events of Special Interest (AESI)
Incidence of AESIs, through Day 183 for PXVX0317 (CHIKV VLP vaccine) and placebo for all age strata combined (safety population).
Time frame: 182 days post-vaccination
Population: Safety population (vaccinated participants who provided safety assessment data), All ages pooled
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Group 1 | Incidence of Adverse Events of Special Interest (AESI) | 3 Participants |
| Group 2 | Incidence of Adverse Events of Special Interest (AESI) | 2 Participants |
| Group 3 | Incidence of Adverse Events of Special Interest (AESI) | 1 Participants |
| Group 4 | Incidence of Adverse Events of Special Interest (AESI) | 1 Participants |
Primary
Incidence of Medically Attended Adverse Event (MAAE)
Incidence of MAAEs through Day 183 for PXVX0317 (CHIKV VLP vaccine) and placebo for all age strata combined (safety population).
Time frame: 182 days post-vaccination
Population: Safety population (vaccinated participants who provided safety assessment data), All ages pooled
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Group 1 | Incidence of Medically Attended Adverse Event (MAAE) | 81 Participants |
| Group 2 | Incidence of Medically Attended Adverse Event (MAAE) | 83 Participants |
| Group 3 | Incidence of Medically Attended Adverse Event (MAAE) | 85 Participants |
| Group 4 | Incidence of Medically Attended Adverse Event (MAAE) | 42 Participants |
Primary
Incidence of Serious Adverse Event (SAE)
Incidence of SAEs through Day 183 for PXVX0317 (CHIKV VLP vaccine) and placebo for all age strata combined (safety population).
Time frame: 182 days post-vaccination
Population: Safety population (vaccinated participants who provided safety assessment data), All ages pooled
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Group 1 | Incidence of Serious Adverse Event (SAE) | 10 Participants |
| Group 2 | Incidence of Serious Adverse Event (SAE) | 7 Participants |
| Group 3 | Incidence of Serious Adverse Event (SAE) | 6 Participants |
| Group 4 | Incidence of Serious Adverse Event (SAE) | 1 Participants |
Primary
Incidence of Solicited Adverse Events (AE)
Incidence of solicited AEs through Day 8 for PXVX0317 (CHIKV VLP vaccine) and placebo for all age strata combined (safety population).
Time frame: 7 days post-vaccination
Population: The number of participants assessed is the number of safety population participants who completed a memory aid following the vaccination.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Group 1 | Incidence of Solicited Adverse Events (AE) | 319 Participants |
| Group 2 | Incidence of Solicited Adverse Events (AE) | 373 Participants |
| Group 3 | Incidence of Solicited Adverse Events (AE) | 366 Participants |
| Group 4 | Incidence of Solicited Adverse Events (AE) | 124 Participants |
Primary
Incidence of Unsolicited AEs
Incidence of unsolicited AEs through Day 29 for PXVX0317 (CHIKV VLP vaccine) and placebo for all age strata combined (safety population).
Time frame: 28 days post-vaccination
Population: Safety population (vaccinated participants who provided safety assessment data), All ages pooled
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Group 1 | Incidence of Unsolicited AEs | 139 Participants |
| Group 2 | Incidence of Unsolicited AEs | 146 Participants |
| Group 3 | Incidence of Unsolicited AEs | 155 Participants |
| Group 4 | Incidence of Unsolicited AEs | 62 Participants |
Secondary
Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183
Anti-CHIKV SNA GMTs with associated 95% CIs at Day 8, Day 15, and Day 183 for PXVX0317 (CHIKV VLP vaccine) and placebo for the IEP, all age strata combined. Number analyzed is number of participants with a sample result available at the indicated visit.
Time frame: Day 8, 15, and 183 (7, 14, and 182 days post-vaccination, respectively)
Population: Immunogenicity evaluable population (randomized and vaccinated participants who provided an evaluable Day 22 anti-CHIKV SNA sample within the analysis window, had no measurable anti-CHIKV SNA titer at Day 1, and had no reason to be excluded as defined prior to unblinding). Groups 1, 2, and 3 are combined, as participants received same treatment of PXVX0317 (dose, adjuvant, schedule), with only difference being the lot of manufactured vaccine. Data is reported for PXVX0317 vaccinated vs. placebo.
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| Group 1 | Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 | Day 8 | 93 Titer |
| Group 1 | Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 | Day 15 | 1096 Titer |
| Group 1 | Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 | Day 183 | 338 Titer |
| Group 2 | Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 | Day 8 | 7 Titer |
| Group 2 | Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 | Day 15 | 8 Titer |
| Group 2 | Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 | Day 183 | 8 Titer |
Comparison: Day 8p-value: <0.000195% CI: [11, 14]ANOVA
Comparison: Day 15p-value: <0.000195% CI: [128, 162]ANOVA
Comparison: Day 183p-value: <0.000195% CI: [37, 46]ANOVA
Secondary
Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 (Data Reported Per Arm)
Anti-CHIKV SNA GMTs with associated 95% CIs at Day 8, Day 15, and Day 183 for PXVX0317 (CHIKV VLP vaccine) and placebo for the IEP, all age strata combined. Number analyzed is number of participants with a sample result available at the indicated visit
Time frame: Day 8, 15, and 183 (7, 14, and 182 days post-vaccination, respectively)
Population: Immunogenicity evaluable population (randomized and vaccinated participants who provided an evaluable Day 22 anti-CHIKV SNA sample within the analysis window, had no measurable anti-CHIKV SNA titer at Day 1, and had no reason to be excluded as defined prior to unblinding).
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| Group 1 | Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 (Data Reported Per Arm) | Day 15 | 1073 Titer |
| Group 1 | Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 (Data Reported Per Arm) | Day 8 | 90 Titer |
| Group 1 | Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 (Data Reported Per Arm) | Day 183 | 331 Titer |
| Group 2 | Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 (Data Reported Per Arm) | Day 15 | 1112 Titer |
| Group 2 | Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 (Data Reported Per Arm) | Day 8 | 97 Titer |
| Group 2 | Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 (Data Reported Per Arm) | Day 183 | 342 Titer |
| Group 3 | Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 (Data Reported Per Arm) | Day 8 | 93 Titer |
| Group 3 | Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 (Data Reported Per Arm) | Day 183 | 340 Titer |
| Group 3 | Anti-CHIKV SNA Geometric Mean Titers (GMTs) at Days 8, 15, and 183 (Data Reported Per Arm) | Day 15 | 1102 Titer |
Secondary
Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8
Anti-CHIKV SNA seroresponse rates for PXVX0317 (CHIKV VLP vaccine) and placebo, difference (PXVX0317 minus placebo), and associated 95% CIs at Day 15, Day 183, and Day 8, in that order, for the IEP, all age strata combined. Number analyzed is number of participants with a sample result available at the indicated visit.
Time frame: Day 15, 183, and 8 (14, 182, and 7 days post-vaccination, respectively)
Population: Immunogenicity evaluable population (randomized and vaccinated participants who provided an evaluable Day 22 anti-CHIKV SNA sample within the analysis window, had no measurable anti-CHIKV SNA titer at Day 1, and had no reason to be excluded as defined prior to unblinding). Groups 1, 2, and 3 are combined, as participants received same treatment of PXVX0317 (dose, adjuvant, schedule), with only difference being the lot of manufactured vaccine. Data is reported for PXVX0317 vaccinated vs. placebo.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Group 1 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 | Day 15 | 96.8 percentage of participants |
| Group 1 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 | Day 183 | 85.5 percentage of participants |
| Group 1 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 | Day 8 | 46.6 percentage of participants |
| Group 2 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 | Day 15 | 0.8 percentage of participants |
| Group 2 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 | Day 183 | 1.5 percentage of participants |
| Group 2 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 | Day 8 | 0.5 percentage of participants |
Comparison: Day 15p-value: <0.000195% CI: [94.3, 96.8]Chi-squared
Comparison: Day 183p-value: <0.000195% CI: [81.7, 85.6]Chi-squared
Comparison: Day 8p-value: <0.000195% CI: [43.8, 48.1]Chi-squared
Secondary
Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 (Data Reported Per Arm)
Anti-CHIKV SNA seroresponse rates and associated 95% CIs for PXVX0317 (CHIKV VLP vaccine) and placebo at Day 15, Day 183, and Day 8, in that order, for the IEP, all age strata combined. Number analyzed is number of participants with a sample result available at the indicated visit.
Time frame: Day 15, 183, and 8 (14, 182, and 7 days post-vaccination, respectively)
Population: Immunogenicity evaluable population (randomized and vaccinated participants who provided an evaluable Day 22 anti-CHIKV SNA sample within the analysis window, had no measurable anti-CHIKV SNA titer at Day 1, and had no reason to be excluded as defined prior to unblinding).
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Group 1 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 (Data Reported Per Arm) | Day 15 | 96.6 percentage of participants |
| Group 1 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 (Data Reported Per Arm) | Day 8 | 45.8 percentage of participants |
| Group 1 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 (Data Reported Per Arm) | Day 183 | 84.6 percentage of participants |
| Group 2 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 (Data Reported Per Arm) | Day 15 | 97.1 percentage of participants |
| Group 2 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 (Data Reported Per Arm) | Day 8 | 47.8 percentage of participants |
| Group 2 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 (Data Reported Per Arm) | Day 183 | 85.9 percentage of participants |
| Group 3 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 (Data Reported Per Arm) | Day 183 | 86.0 percentage of participants |
| Group 3 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 (Data Reported Per Arm) | Day 15 | 96.5 percentage of participants |
| Group 3 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 (Data Reported Per Arm) | Day 8 | 46.1 percentage of participants |
| Group 4 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 (Data Reported Per Arm) | Day 15 | 0.8 percentage of participants |
| Group 4 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 (Data Reported Per Arm) | Day 8 | 0.5 percentage of participants |
| Group 4 | Anti-CHIKV SNA Seroresponse Rates at Days 15, 183, and 8 (Data Reported Per Arm) | Day 183 | 1.5 percentage of participants |
Secondary
Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183
Geometric mean fold increase (GMFI) in anti-CHIKV SNA titers from Day 1 to Day 8, Day 15, Day 22, and Day 183 for the IEP for all age strata combined. Fold rise in geometric mean titer is the ratio of the post-baseline value to the baseline value (e.g. number of 2 represents a post-baseline doubling of geometric mean titer). Number analyzed is number of participants with a sample result available at both Day 1 and the indicated visit.
Time frame: Day 8, 15, 22, and 183 (7,14, 21, and 182 days post-vaccination, respectively)
Population: Immunogenicity evaluable population (randomized and vaccinated participants who provided an evaluable Day 22 anti-CHIKV SNA sample within the analysis window, had no measurable anti-CHIKV SNA titer at Day 1, and had no reason to be excluded as defined prior to unblinding). Groups 1, 2, and 3 are combined, as participants received same treatment of PXVX0317 (dose, adjuvant, schedule), with only difference being the lot of manufactured vaccine. Data is reported for PXVX0317 vaccinated vs. placebo.
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| Group 1 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 | Day 8 | 12.5 Fold rise from baseline |
| Group 1 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 | Day 15 | 146.1 Fold rise from baseline |
| Group 1 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 | Day 22 | 215.7 Fold rise from baseline |
| Group 1 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 | Day 183 | 45.0 Fold rise from baseline |
| Group 2 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 | Day 183 | 1.1 Fold rise from baseline |
| Group 2 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 | Day 8 | 1.0 Fold rise from baseline |
| Group 2 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 | Day 22 | 1.1 Fold rise from baseline |
| Group 2 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 | Day 15 | 1.0 Fold rise from baseline |
Comparison: Day 8p-value: <0.0001t-test, 2 sided
Comparison: Day 15p-value: <0.0001t-test, 2 sided
Comparison: Day 22p-value: <0.0001t-test, 2 sided
Comparison: Day 183p-value: <0.0001t-test, 2 sided
Secondary
Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 (Data Reported Per Arm)
Geometric mean fold increase (GMFI) in anti-CHIKV SNA titers from Day 1 to Day 8, Day 15, Day 22, and Day 183 for the IEP for all age strata combined. Fold rise in geometric mean titer is the ratio of the post-baseline value to the baseline value (e.g. number of 2 represents a post-baseline doubling of geometric mean titer). Number analyzed is number of participants with a sample result available at both Day 1 and the indicated visit.
Time frame: Day 8, 15, 22, and 183 (7,14, 21, and 182 days post-vaccination, respectively)
Population: Immunogenicity evaluable population (randomized and vaccinated participants who provided an evaluable Day 22 anti-CHIKV SNA sample within the analysis window, had no measurable anti-CHIKV SNA titer at Day 1, and had no reason to be excluded as defined prior to unblinding).
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| Group 1 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 (Data Reported Per Arm) | Day 8 | 12.0 Fold rise from baseline |
| Group 1 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 (Data Reported Per Arm) | Day 15 | 143.1 Fold rise from baseline |
| Group 1 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 (Data Reported Per Arm) | Day 22 | 212.3 Fold rise from baseline |
| Group 1 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 (Data Reported Per Arm) | Day 183 | 44.1 Fold rise from baseline |
| Group 2 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 (Data Reported Per Arm) | Day 183 | 45.6 Fold rise from baseline |
| Group 2 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 (Data Reported Per Arm) | Day 8 | 12.9 Fold rise from baseline |
| Group 2 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 (Data Reported Per Arm) | Day 22 | 218.6 Fold rise from baseline |
| Group 2 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 (Data Reported Per Arm) | Day 15 | 148.3 Fold rise from baseline |
| Group 3 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 (Data Reported Per Arm) | Day 183 | 45.4 Fold rise from baseline |
| Group 3 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 (Data Reported Per Arm) | Day 15 | 147.0 Fold rise from baseline |
| Group 3 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 (Data Reported Per Arm) | Day 22 | 216.3 Fold rise from baseline |
| Group 3 | Geometric Mean Fold Increase (GMFI) in Anti-CHIKV SNA Titers From Day 1 to Days 8, 15, 22, and 183 (Data Reported Per Arm) | Day 8 | 12.5 Fold rise from baseline |
Secondary
Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183
Number and percentage of participants with anti-CHIKV SNA titers ≥15 and 4-fold rise over baseline at Day 8, Day 15, Day 22, and Day 183 for the IEP for all age strata combined. Number analyzed is number of participants with a sample result available at the indicated visit.
Time frame: Day 8, 15, 22, and 183 (7,14, 21, and 182 days post-vaccination, respectively)
Population: Immunogenicity evaluable population (randomized and vaccinated participants who provided an evaluable Day 22 anti-CHIKV SNA sample within the analysis window, had no measurable anti-CHIKV SNA titer at Day 1, and had no reason to be excluded as defined prior to unblinding). Groups 1, 2, and 3 are combined, as participants received same treatment of PXVX0317 (dose, adjuvant, schedule), with only difference being the lot of manufactured vaccine. Data is reported for PXVX0317 vaccinated vs. placebo.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Group 1 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | SNA titers ≥15 at Day 8 | 91.9 percentage of participants |
| Group 1 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | SNA titers ≥15 at Day 15 | 99.5 percentage of participants |
| Group 1 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | SNA titers ≥15 at Day 22 | 99.2 percentage of participants |
| Group 1 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | SNA titers ≥15 at Day 183 | 99.0 percentage of participants |
| Group 1 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | ≥4-fold rise over baseline at Day 8 | 65.5 percentage of participants |
| Group 1 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | ≥4-fold rise over baseline at Day 15 | 98.6 percentage of participants |
| Group 1 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | ≥4-fold rise over baseline at Day 22 | 98.6 percentage of participants |
| Group 1 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | ≥4-fold rise over baseline at Day 183 | 92.9 percentage of participants |
| Group 2 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | ≥4-fold rise over baseline at Day 183 | 1.5 percentage of participants |
| Group 2 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | SNA titers ≥15 at Day 8 | 1.2 percentage of participants |
| Group 2 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | ≥4-fold rise over baseline at Day 8 | 0.7 percentage of participants |
| Group 2 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | SNA titers ≥15 at Day 15 | 0.8 percentage of participants |
| Group 2 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | ≥4-fold rise over baseline at Day 22 | 1.4 percentage of participants |
| Group 2 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | SNA titers ≥15 at Day 22 | 1.7 percentage of participants |
| Group 2 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | ≥4-fold rise over baseline at Day 15 | 0.8 percentage of participants |
| Group 2 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 | SNA titers ≥15 at Day 183 | 2.2 percentage of participants |
Comparison: SNA titers ≥15 at Day 8p-value: <0.000195% CI: [88.7, 91.9]Chi-squared
Comparison: SNA titers ≥15 at Day 15p-value: <0.000195% CI: [97.2, 99.3]Chi-squared
Comparison: SNA titers ≥15 at Day 22p-value: <0.000195% CI: [95.8, 98.5]Chi-squared
Comparison: SNA titers ≥15 at Day 183p-value: <0.000195% CI: [94.8, 97.9]Chi-squared
Comparison: ≥4-fold rise over baseline at Day 8p-value: <0.000195% CI: [62.5, 66.7]Chi-squared
Comparison: ≥4-fold rise over baseline at Day 15p-value: <0.000195% CI: [96.3, 98.4]Chi-squared
Comparison: ≥4-fold rise over baseline at Day 22p-value: <0.000195% CI: [95.5, 98.1]Chi-squared
Comparison: ≥4-fold rise over baseline at Day 183p-value: <0.000195% CI: [89.4, 92.7]Chi-squared
Secondary
Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm)
Number and percentage of participants with anti-CHIKV SNA titers ≥15 and 4-fold rise over baseline at Day 8, Day 15, Day 22, and Day 183 for the IEP for all age strata combined. Number analyzed is number of participants with a sample result available at the indicated visit.
Time frame: Day 8, 15, 22, and 183 (7,14, 21, and 182 days post-vaccination, respectively)
Population: Immunogenicity evaluable population (randomized and vaccinated participants who provided an evaluable Day 22 anti-CHIKV SNA sample within the analysis window, had no measurable anti-CHIKV SNA titer at Day 1, and had no reason to be excluded as defined prior to unblinding).
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Group 1 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | SNA titers ≥15 at Day 8 | 90.9 percentage of participants |
| Group 1 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | SNA titers ≥15 at Day 15 | 99.4 percentage of participants |
| Group 1 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | SNA titers ≥15 at Day 22 | 99.3 percentage of participants |
| Group 1 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | SNA titers ≥15 at Day 183 | 98.9 percentage of participants |
| Group 1 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | ≥4-fold rise over baseline at Day 8 | 66.7 percentage of participants |
| Group 1 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | ≥4-fold rise over baseline at Day 15 | 98.1 percentage of participants |
| Group 1 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | ≥4-fold rise over baseline at Day 22 | 98.7 percentage of participants |
| Group 1 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | ≥4-fold rise over baseline at Day 183 | 92.0 percentage of participants |
| Group 2 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | SNA titers ≥15 at Day 22 | 99.2 percentage of participants |
| Group 2 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | ≥4-fold rise over baseline at Day 22 | 98.7 percentage of participants |
| Group 2 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | SNA titers ≥15 at Day 183 | 99.0 percentage of participants |
| Group 2 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | ≥4-fold rise over baseline at Day 8 | 66.0 percentage of participants |
| Group 2 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | ≥4-fold rise over baseline at Day 15 | 98.8 percentage of participants |
| Group 2 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | SNA titers ≥15 at Day 8 | 93.6 percentage of participants |
| Group 2 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | SNA titers ≥15 at Day 15 | 99.5 percentage of participants |
| Group 2 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | ≥4-fold rise over baseline at Day 183 | 93.5 percentage of participants |
| Group 3 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | SNA titers ≥15 at Day 22 | 99.2 percentage of participants |
| Group 3 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | SNA titers ≥15 at Day 15 | 99.5 percentage of participants |
| Group 3 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | SNA titers ≥15 at Day 8 | 91.0 percentage of participants |
| Group 3 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | SNA titers ≥15 at Day 183 | 99.2 percentage of participants |
| Group 3 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | ≥4-fold rise over baseline at Day 22 | 98.5 percentage of participants |
| Group 3 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | ≥4-fold rise over baseline at Day 15 | 98.8 percentage of participants |
| Group 3 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | ≥4-fold rise over baseline at Day 8 | 63.7 percentage of participants |
| Group 3 | Number and Percentage of Participants With Anti-CHIKV SNA Titer ≥15 and 4-fold Rise Over Baseline at Days 8, 15, 22, and 183 (Data Reported Per Arm) | ≥4-fold rise over baseline at Day 183 | 93.2 percentage of participants |