Chikungunya
Conditions
Brief summary
This was a phase 2 parallel-group age- and gender-matched open label study in healthy adults 18-65 years of age to assess the safety and immunogenicity of an alum-adjuvanted chikungunya virus-like particle vaccine (PXVX0317; CHIKV VLP vaccine) in prior recipients of other alphavirus vaccines versus alphavirus naïve controls.
Detailed description
It is currently unknown whether prior exposure to heterologous alphaviruses will enhance or interfere with immune responses to chikungunya virus (CHIKV) exposure or vaccination. The objective of this study was to evaluate the safety and immunogenicity of the chikungunya vaccine candidate PXVX0317 when administered to prior recipients of experimental alphavirus vaccines versus alphavirus naïve gender- and age-matched controls.
Interventions
BIOLOGICALChikungunya
Virus Like Particle
Sponsors
Walter Reed Army Institute of Research (WRAIR)
Emergent BioSolutions
Bavarian Nordic
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Intervention model description
Open Label Safety and Immunogenicity
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Age 18 to 65 years old (inclusive) * For women of childbearing potential, a negative pregnancy test at screening and on vaccination day, practicing highly effective contraception for at least 30 days prior to vaccination, and willing to use a highly effective method of contraception through study completion. * Able and willing to provide informed consent for study participation prior to screening procedures. * Free of obvious health problems as established by medical history and clinical examination at screening and enrollment. * Available to participate for the duration of the study (approximately 8 months). * For the cohort of prior alphavirus vaccine recipients, a documented history of prior alphavirus vaccination.
Exclusion criteria
* Acute disease or febrile illness at the time of screening or enrollment. * Clinically significant cardiac, respiratory, rheumatologic or other medical or psychiatric condition that, in the opinion of the Investigator, places the subject at increased risk or affects their ability to understand and comply with study procedures. * Abnormal screening lab test result that, in the opinion of the investigator, obscures interpretation of the safety data or suggests a clinically significant cardiac, respiratory, rheumatologic or other medical condition that places the subject at increased risk. * Pregnant, lactating or planning to become pregnant during the study period. * Laboratory evidence of infection with Hepatitis B, C or HIV. * History of naturally (non-laboratory) acquired chikungunya or other alphavirus infection or travel to a WHO-designated chikungunya-endemic region within 30 days prior to Day 1. * History of acute allergic reaction to any component of CHIKV VLP vaccine or Alhydrogel®. * Current (30 days prior to Day 1) or anticipated use of systemic immunomodulatory or immunosuppressive medications. * History of splenectomy, immunosuppressive condition, autoimmune disease, or immunodeficient condition. * Family history of congenital or hereditary immunodeficiency. * Suspected or known current alcohol abuse that, in the opinion of the Investigator, would interfere with the subject's ability to understand and comply with study procedures. * Current intravenous drug use. * Prior receipt of an investigational chikungunya vaccine. * Receipt or planned receipt of any licensed vaccine from 30 days prior to Day 1 through Day 29 study visit. * Participation in another clinical trial during the study period in which an investigational product is administered. * For the alphavirus naïve group, history of prior alphavirus vaccination is exclusionary.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response | Day 22 (21 days after vaccination) | Seroconversion, defined as a 4-fold or greater rise in neutralizing antibody against chikungunya virus, as determined by luciferase-based assay (NT80), induced by PXVX0317. PXVX0317 was administered to prior alphavirus vaccine recipients versus gender- and age-matched controls. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response | Day 8, 29, 57, 182 | Evaluation of seroconversion rate of Anti-CHIKV neutralizing antibodies, determined by luciferase-based assay (NT80), in prior alphavirus vaccine recipients versus alphavirus-naïve controls. |
| Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 1, 8, 22, 29, 57, 182 | Evaluation of Anti-CHIKV neutralizing antibody response, as determined by luciferase-based assay (NT80), via proportion of participants with titers of at least 40, 160 or 640 on Days 1, 8, 22, 29, 57 and 182. |
| Geometric Mean Titer of Anti-CHIKV Total Antibody Response | Day 1, 22, 29 | Evaluation of Geometric Mean Titer of Anti-CHIKV total antibodies, determined by immunoassay (ELISA), in prior alphavirus vaccine recipients versus alphavirus-naïve controls. |
| Percentage of Participants With 4-fold Rise in Anti-CHIKV Total Antibody Response | Day 22, 29 | Evaluation of seroconversion rate of Anti-CHIKV total antibodies, determined by immunoassay, on Days 22 and 29, where seroconversion was a 4-fold rise in titer over baseline. |
| Geometric Mean Titer of Anti-VEEV Neutralizing Antibody Response | Day 1, 22, 29 | Evaluation of Geometric Mean Titer of Anti-VEEV neutralizing antibodies, determined by Plaque-Reduction Neutralization Test (PRNT80), in prior alphavirus vaccine recipients versus alphavirus-naïve controls |
| Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response | Day 1, 8, 22, 29, 57, 182 | Evaluation of Geometric Mean Titer of Anti-CHIKV neutralizing antibodies, determined by luciferase-based assay (NT80), in prior alphavirus vaccine recipients versus alphavirus-naïve controls. |
| Percentage of Participants With 4-fold Rise in Anti-VEEV Neutralizing Antibody Response | Day 22 and 29 | Evaluation of seroconversion rate of anti-VEEV neutralizing antibodies on Days 22 and 29 as determined by Plaque-Reduction Neutralization Test (PRNT80), where seroconversion is a 4-fold rise in titer over baseline. |
| Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 1, 22, 29 | Evaluation of Anti-VEEV neutralizing antibody response, as determined by Plaque-Reduction Neutralization Test (PRNT80), via proportion of participants with titers of at least 40, 160 or 640 on Days 1, 22 and 29. |
| Geometric Mean Titer of Anti-VEEV Total Antibody Response | Day 1, 22, 29 | Evaluation of Geometric Mean Titer of Anti-VEEV total antibody as determined by an immunoassay (ELISA) in prior alphavirus vaccine recipients versus alphavirus-naïve controls. |
| Percentage of Participants With 4-fold Rise in Total ELISA IgG Antibody Against VEEV | Day 22, 29 | Evaluation of seroconversion rate of Anti-VEEV total antibody, as determined by immunoassay (ELISA), on Days 22 and 29, where seroconversion is a 4-fold rise in titer over baseline. |
| Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Days 1, 22, and 29 | Evaluation of Anti-VEEV total antibody titer, as determined by immunoassay (ELISA), via proportion of participants with titers of at least 40, 160, or 640 on Days 1, 22, and 29. |
| Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Days 1, 22, and 29 | Evaluation of Anti-CHIKV total antibody titer, as determined by immunoassay (ELISA), via proportion of participants with titers of at least 40, 160 or 640 on Days 1, 22, and 29. |
Countries
United States
Participant flow
Recruitment details
Participants were recruited from two US sites, Walter Reed Army Institute of Research (WRAIR) Clinical Trials Center (CTC) and US Army Medical Research Institute for Infectious Disease (USAMRIID) immunization clinic.
Participants by arm
| Arm | Count |
|---|---|
| Experimental : Prior Alpha All study participants received the same Investigational Product according to the same schedule. Subjects were prior recipients of experimental alphavirus vaccines. | 30 |
| Control: Naive Alpha All study participants received the same Investigational Product according to the same schedule. The alphavirus vaccine naïve subjects serves as controls. | 30 |
| Total | 60 |
Baseline characteristics
| Characteristic | Experimental : Prior Alpha | Total | Control: Naive Alpha |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 30 Participants | 60 Participants | 30 Participants |
| BMI | 31.04 Kg/m^2 STANDARD_DEVIATION 6.11 | 30.91 Kg/m^2 STANDARD_DEVIATION 5.42 | 30.78 Kg/m^2 STANDARD_DEVIATION 4.72 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 2 Participants | 3 Participants | 1 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 28 Participants | 57 Participants | 29 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Height | 171.12 cm STANDARD_DEVIATION 11.37 | 173.11 cm STANDARD_DEVIATION 11.35 | 175.10 cm STANDARD_DEVIATION 11.16 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants | 4 Participants | 3 Participants |
| Race (NIH/OMB) Black or African American | 2 Participants | 14 Participants | 12 Participants |
| Race (NIH/OMB) More than one race | 1 Participants | 2 Participants | 1 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 26 Participants | 40 Participants | 14 Participants |
| Sex: Female, Male Female | 10 Participants | 20 Participants | 10 Participants |
| Sex: Female, Male Male | 20 Participants | 40 Participants | 20 Participants |
| Time Since Prior Alphavirus Vaccine | 16.2 years STANDARD_DEVIATION 8.3 | 16.2 years STANDARD_DEVIATION 8.3 | NA years |
| Weight | 90.99 Kg STANDARD_DEVIATION 19.19 | 92.82 Kg STANDARD_DEVIATION 18.6 | 94.64 Kg STANDARD_DEVIATION 18.14 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 30 | 0 / 30 |
| other Total, other adverse events | 17 / 30 | 17 / 30 |
| serious Total, serious adverse events | 0 / 30 | 1 / 30 |
Outcome results
Primary
Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response
Seroconversion, defined as a 4-fold or greater rise in neutralizing antibody against chikungunya virus, as determined by luciferase-based assay (NT80), induced by PXVX0317. PXVX0317 was administered to prior alphavirus vaccine recipients versus gender- and age-matched controls.
Time frame: Day 22 (21 days after vaccination)
Population: Immunogenicity evaluable population
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Experimental: Prior Alpha | Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response | 100 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response | 100 percentage of participants |
p-value: 195% CI: [-11.4, 11.4]Fisher Exact
Secondary
Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response
Evaluation of Geometric Mean Titer of Anti-CHIKV neutralizing antibodies, determined by luciferase-based assay (NT80), in prior alphavirus vaccine recipients versus alphavirus-naïve controls.
Time frame: Day 1, 8, 22, 29, 57, 182
Population: Immunogenicity evaluable population
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| Experimental: Prior Alpha | Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response | Day 1 | 9.21 titers |
| Experimental: Prior Alpha | Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response | Day 8 | 271.88 titers |
| Experimental: Prior Alpha | Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response | Day 22 | 2032.45 titers |
| Experimental: Prior Alpha | Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response | Day 29 | 1555.60 titers |
| Experimental: Prior Alpha | Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response | Day 57 | 727.91 titers |
| Experimental: Prior Alpha | Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response | Day 182 | 294.35 titers |
| Control: Naive Alpha | Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response | Day 57 | 814.64 titers |
| Control: Naive Alpha | Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response | Day 1 | 7.69 titers |
| Control: Naive Alpha | Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response | Day 29 | 1772.54 titers |
| Control: Naive Alpha | Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response | Day 8 | 87.48 titers |
| Control: Naive Alpha | Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response | Day 182 | 328.89 titers |
| Control: Naive Alpha | Geometric Mean Titer of Anti-CHIKV Neutralizing Antibody Response | Day 22 | 2299.18 titers |
Comparison: Day 1: Geometric mean ratio (prior alpha group over naïve alpha group) and 95% confidence interval
Comparison: Day 8: Geometric mean ratio (prior alpha group over naïve alpha group) and 95% confidence intervalp-value: 0.001995% CI: [1.55, 6.23]ANOVA
Comparison: Day 22: Geometric mean ratio (prior alpha group over naïve alpha group) and 95% confidence intervalp-value: 0.622395% CI: [0.54, 1.46]ANOVA
Comparison: Day 29: Geometric mean ratio (prior alpha group over naïve alpha group) and 95% confidence intervalp-value: 0.644495% CI: [0.5, 1.55]ANOVA
Comparison: Day 57: Geometric mean ratio (prior alpha group over naïve alpha group) and 95% confidence intervalp-value: 0.619895% CI: [0.57, 1.41]ANOVA
Comparison: Day 182: Geometric mean ratio (prior alpha group over naïve alpha group) and 95% confidence intervalp-value: 0.645195% CI: [0.55, 1.45]ANOVA
Secondary
Geometric Mean Titer of Anti-CHIKV Total Antibody Response
Evaluation of Geometric Mean Titer of Anti-CHIKV total antibodies, determined by immunoassay (ELISA), in prior alphavirus vaccine recipients versus alphavirus-naïve controls.
Time frame: Day 1, 22, 29
Population: Immunogenicity evaluable population
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| Experimental: Prior Alpha | Geometric Mean Titer of Anti-CHIKV Total Antibody Response | Day 1 | 39.03 titers |
| Experimental: Prior Alpha | Geometric Mean Titer of Anti-CHIKV Total Antibody Response | Day 22 | 2451.60 titers |
| Experimental: Prior Alpha | Geometric Mean Titer of Anti-CHIKV Total Antibody Response | Day 29 | 2010.72 titers |
| Control: Naive Alpha | Geometric Mean Titer of Anti-CHIKV Total Antibody Response | Day 1 | 25.77 titers |
| Control: Naive Alpha | Geometric Mean Titer of Anti-CHIKV Total Antibody Response | Day 22 | 1338.90 titers |
| Control: Naive Alpha | Geometric Mean Titer of Anti-CHIKV Total Antibody Response | Day 29 | 1194.75 titers |
Comparison: Day 1: Geometric mean ratio (prior alpha group over naïve alpha group) and 95% confidence intervalp-value: 0.027795% CI: [1.05, 2.19]ANOVA
Comparison: Day 22: Geometric mean ratio (prior alpha group over naïve alpha group) and 95% confidence intervalp-value: 0.008895% CI: [1.17, 2.86]ANOVA
Comparison: Day 29: Geometric mean ratio (prior alpha group over naïve alpha group) and 95% confidence intervalp-value: 0.047595% CI: [1.01, 2.82]ANOVA
Secondary
Geometric Mean Titer of Anti-VEEV Neutralizing Antibody Response
Evaluation of Geometric Mean Titer of Anti-VEEV neutralizing antibodies, determined by Plaque-Reduction Neutralization Test (PRNT80), in prior alphavirus vaccine recipients versus alphavirus-naïve controls
Time frame: Day 1, 22, 29
Population: Immunogenicity evaluable population
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| Experimental: Prior Alpha | Geometric Mean Titer of Anti-VEEV Neutralizing Antibody Response | Day 22 | 467.95 titers |
| Experimental: Prior Alpha | Geometric Mean Titer of Anti-VEEV Neutralizing Antibody Response | Day 1 | 449.82 titers |
| Experimental: Prior Alpha | Geometric Mean Titer of Anti-VEEV Neutralizing Antibody Response | Day 29 | 538.63 titers |
| Control: Naive Alpha | Geometric Mean Titer of Anti-VEEV Neutralizing Antibody Response | Day 1 | 9.96 titers |
| Control: Naive Alpha | Geometric Mean Titer of Anti-VEEV Neutralizing Antibody Response | Day 22 | 9.89 titers |
| Control: Naive Alpha | Geometric Mean Titer of Anti-VEEV Neutralizing Antibody Response | Day 29 | 9.66 titers |
Comparison: Day 1: Geometric mean ratio (prior alpha group over naïve alpha group) and 95% confidence interval
Comparison: Day 22: Geometric mean ratio (prior alpha group over naïve alpha group) and 95% confidence interval
Comparison: Day 29: Geometric mean ratio (prior alpha group over naïve alpha group) and 95% confidence interval
Secondary
Geometric Mean Titer of Anti-VEEV Total Antibody Response
Evaluation of Geometric Mean Titer of Anti-VEEV total antibody as determined by an immunoassay (ELISA) in prior alphavirus vaccine recipients versus alphavirus-naïve controls.
Time frame: Day 1, 22, 29
Population: Immunogenicity evaluable population. 11 alphavirus naïve participants were unable to attend their scheduled visit at Day 29.
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| Experimental: Prior Alpha | Geometric Mean Titer of Anti-VEEV Total Antibody Response | Day 1 | 324.36 titers |
| Experimental: Prior Alpha | Geometric Mean Titer of Anti-VEEV Total Antibody Response | Day 22 | 2574.16 titers |
| Experimental: Prior Alpha | Geometric Mean Titer of Anti-VEEV Total Antibody Response | Day 29 | 2006.14 titers |
| Control: Naive Alpha | Geometric Mean Titer of Anti-VEEV Total Antibody Response | Day 1 | 14.03 titers |
| Control: Naive Alpha | Geometric Mean Titer of Anti-VEEV Total Antibody Response | Day 22 | 14.92 titers |
| Control: Naive Alpha | Geometric Mean Titer of Anti-VEEV Total Antibody Response | Day 29 | 16.94 titers |
Comparison: Day 1: Geometric mean ratio (prior alpha group over naïve alpha group) and 95% confidence intervalp-value: <0.000195% CI: [11.54, 46.35]ANOVA
Comparison: Day 22: Geometric mean ratio (prior alpha group over naïve alpha group) and 95% confidence intervalp-value: <0.000195% CI: [106.6, 279.19]ANOVA
Comparison: Day 29: Geometric mean ratio (prior alpha group over naive alpha group) and 95% confidence intervalp-value: <0.000195% CI: [61.76, 227.16]ANOVA
Secondary
Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640
Evaluation of Anti-CHIKV total antibody titer, as determined by immunoassay (ELISA), via proportion of participants with titers of at least 40, 160 or 640 on Days 1, 22, and 29.
Time frame: Days 1, 22, and 29
Population: Immunogenicity evaluable population. 11 alphavirus naive participants were unable to attend their scheduled visit at Day 29.
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Experimental: Prior Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 1 Titers >=40 | 15 Participants |
| Experimental: Prior Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 22 Titers >=640 | 30 Participants |
| Experimental: Prior Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 22 Titers >=40 | 30 Participants |
| Experimental: Prior Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 29 Titers >=40 | 30 Participants |
| Experimental: Prior Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 1 Titers >=640 | 0 Participants |
| Experimental: Prior Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 29 Titers >=160 | 30 Participants |
| Experimental: Prior Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 22 Titers >=160 | 30 Participants |
| Experimental: Prior Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 29 Titers >=640 | 30 Participants |
| Experimental: Prior Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 1 Titers >=160 | 4 Participants |
| Control: Naive Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 29 Titers >=640 | 17 Participants |
| Control: Naive Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 1 Titers >=40 | 4 Participants |
| Control: Naive Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 1 Titers >=160 | 1 Participants |
| Control: Naive Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 1 Titers >=640 | 0 Participants |
| Control: Naive Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 22 Titers >=40 | 30 Participants |
| Control: Naive Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 22 Titers >=160 | 30 Participants |
| Control: Naive Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 22 Titers >=640 | 26 Participants |
| Control: Naive Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 29 Titers >=40 | 19 Participants |
| Control: Naive Alpha | Number of Participants With Anti-CHIKV Total Antibody Titers of at Least 40,160 or 640 | Day 29 Titers >=160 | 19 Participants |
Secondary
Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640
Evaluation of Anti-VEEV total antibody titer, as determined by immunoassay (ELISA), via proportion of participants with titers of at least 40, 160, or 640 on Days 1, 22, and 29.
Time frame: Days 1, 22, and 29
Population: Immunogenicity evaluable population. 11 alphavirus naive participants were unable to attend their scheduled visit at Day 29.
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Experimental: Prior Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 1 Titers >=160 | 23 Participants |
| Experimental: Prior Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 22 Titers >=640 | 17 Participants |
| Experimental: Prior Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 22 Titers >=40 | 27 Participants |
| Experimental: Prior Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 29 Titers >=40 | 27 Participants |
| Experimental: Prior Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 1 Titers >=640 | 16 Participants |
| Experimental: Prior Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 29 Titers >=160 | 25 Participants |
| Experimental: Prior Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 22 Titers >=160 | 24 Participants |
| Experimental: Prior Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 29 Titers >=640 | 18 Participants |
| Experimental: Prior Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 1 Titers >=40 | 27 Participants |
| Control: Naive Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 29 Titers >=640 | 0 Participants |
| Control: Naive Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 1 Titers >=40 | 0 Participants |
| Control: Naive Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 1 Titers >=160 | 0 Participants |
| Control: Naive Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 1 Titers >=640 | 0 Participants |
| Control: Naive Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 22 Titers >=40 | 0 Participants |
| Control: Naive Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 22 Titers >=160 | 0 Participants |
| Control: Naive Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 22 Titers >=640 | 0 Participants |
| Control: Naive Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 29 Titers >=40 | 0 Participants |
| Control: Naive Alpha | Number of Participants With Anti-VEEV Total Antibody Titers of at Least 40,160 or 640 | Day 29 Titers >=160 | 0 Participants |
Secondary
Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response
Evaluation of seroconversion rate of Anti-CHIKV neutralizing antibodies, determined by luciferase-based assay (NT80), in prior alphavirus vaccine recipients versus alphavirus-naïve controls.
Time frame: Day 8, 29, 57, 182
Population: Immunogenicity evaluable population.~11 alphavirus naïve subjects were unable to attend their scheduled visit at Day 29; 10 of those subjects also missed their Day 57 visit.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Experimental: Prior Alpha | Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response | Day 8 | 93.3 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response | Day 29 | 100 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response | Day 57 | 100 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response | Day 182 | 86.7 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response | Day 182 | 100 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response | Day 8 | 66.7 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response | Day 57 | 100 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With 4-fold Rise in Anti-CHIKV Neutralizing Antibody Response | Day 29 | 100 percentage of participants |
p-value: 0.0211Fisher Exact
p-value: 1Fisher Exact
p-value: 1Fisher Exact
p-value: 0.1124Fisher Exact
Secondary
Percentage of Participants With 4-fold Rise in Anti-CHIKV Total Antibody Response
Evaluation of seroconversion rate of Anti-CHIKV total antibodies, determined by immunoassay, on Days 22 and 29, where seroconversion was a 4-fold rise in titer over baseline.
Time frame: Day 22, 29
Population: Immunogenicity evaluable population. 11 alphavirus naïve participants were unable to attend their scheduled visit at Day 29.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Experimental: Prior Alpha | Percentage of Participants With 4-fold Rise in Anti-CHIKV Total Antibody Response | Day 22 | 100 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With 4-fold Rise in Anti-CHIKV Total Antibody Response | Day 29 | 100 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With 4-fold Rise in Anti-CHIKV Total Antibody Response | Day 22 | 100 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With 4-fold Rise in Anti-CHIKV Total Antibody Response | Day 29 | 100 percentage of participants |
p-value: 1Fisher Exact
p-value: 1Fisher Exact
Secondary
Percentage of Participants With 4-fold Rise in Anti-VEEV Neutralizing Antibody Response
Evaluation of seroconversion rate of anti-VEEV neutralizing antibodies on Days 22 and 29 as determined by Plaque-Reduction Neutralization Test (PRNT80), where seroconversion is a 4-fold rise in titer over baseline.
Time frame: Day 22 and 29
Population: Immunogenicity evaluable population. 11 alphavirus naïve participants were unable to attend their scheduled visit at Day 29.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Experimental: Prior Alpha | Percentage of Participants With 4-fold Rise in Anti-VEEV Neutralizing Antibody Response | Day 22 | 0 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With 4-fold Rise in Anti-VEEV Neutralizing Antibody Response | Day 29 | 0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With 4-fold Rise in Anti-VEEV Neutralizing Antibody Response | Day 22 | 0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With 4-fold Rise in Anti-VEEV Neutralizing Antibody Response | Day 29 | 0 percentage of participants |
p-value: 1Fisher Exact
p-value: 1Fisher Exact
Secondary
Percentage of Participants With 4-fold Rise in Total ELISA IgG Antibody Against VEEV
Evaluation of seroconversion rate of Anti-VEEV total antibody, as determined by immunoassay (ELISA), on Days 22 and 29, where seroconversion is a 4-fold rise in titer over baseline.
Time frame: Day 22, 29
Population: Immunogenicity evaluable population. 11 alphavirus naïve participants were unable to attend their scheduled visit at Day 29.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Experimental: Prior Alpha | Percentage of Participants With 4-fold Rise in Total ELISA IgG Antibody Against VEEV | Day 22 | 86.7 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With 4-fold Rise in Total ELISA IgG Antibody Against VEEV | Day 29 | 80.0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With 4-fold Rise in Total ELISA IgG Antibody Against VEEV | Day 22 | 0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With 4-fold Rise in Total ELISA IgG Antibody Against VEEV | Day 29 | 0 percentage of participants |
p-value: <0.0001Fisher Exact
p-value: <0.0001Fisher Exact
Secondary
Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds
Evaluation of Anti-CHIKV neutralizing antibody response, as determined by luciferase-based assay (NT80), via proportion of participants with titers of at least 40, 160 or 640 on Days 1, 8, 22, 29, 57 and 182.
Time frame: Day 1, 8, 22, 29, 57, 182
Population: Immunogenicity evaluable population. 11 alphavirus naïve participants were unable to attend their scheduled visit at Day 29; 10 of those participants also missed their Day 57 visit.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 1 (Titer >=40) | 3.3 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 1 (Titer >=160) | 3.3 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 1 (Titer >=640) | 0 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 8 (Titer >=40) | 96.7 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 8 (Titer >=160) | 70.0 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 8 (Titer >=640) | 26.7 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 22 (Titer >=40) | 100 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 22 (Titer >=160) | 100 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 22 (Titer >=640) | 73.3 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 29 (Titer >=40) | 100 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 29 (Titer >=160) | 100 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 29 (Titer >=640) | 76.7 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 57 (Titer >=40) | 100 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 57 (Titer >=160) | 90.0 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 57 (Titer >=640) | 63.3 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 182 (Titer >=40) | 93.3 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 182 (Titer >=160) | 76.7 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 182 (Titer >=640) | 20.0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 57 (Titer >=160) | 95 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 1 (Titer >=40) | 0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 29 (Titer >=40) | 100 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 1 (Titer >=160) | 0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 182 (Titer >=640) | 30.0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 1 (Titer >=640) | 0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 29 (Titer >=160) | 100 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 8 (Titer >=40) | 73.3 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 57 (Titer >=640) | 75 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 8 (Titer >=160) | 40 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 29 (Titer >=640) | 94.7 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 8 (Titer >=640) | 10.0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 182 (Titer >=160) | 76.7 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 22 (Titer >=40) | 100 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 57 (Titer >=40) | 100 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 22 (Titer >=160) | 100 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 182 (Titer >=40) | 100 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-CHIKV Neutralizing Antibody at or Above Selected Thresholds | Day 22 (Titer >=640) | 93.3 percentage of participants |
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point.~Day 1 : Subjects with Titer \>=40p-value: >0.9999Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point~Day 1: Subjects with Titer \>=160p-value: >0.9999Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point.~Day 1: Subjects with Titer \>=640p-value: 1Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point.~Day 8 : Subjects with Titer \>=40p-value: 0.0257Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point~Day 8: Subjects with Titer \>=160p-value: 0.037Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point.~Day 8: Subjects with Titer \>=640p-value: 0.1806Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point.~Day 22: Subjects with Titer \>=40p-value: 1Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point~Day 22: Subjects with Titer \>=160p-value: 1Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point~Day 22: Subjects with Titer \>=640p-value: 0.0797Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point.~Day 29: Subject with Titer \>=40p-value: 1Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point.~Day 29: Subject with Titer \>=160p-value: 1Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point.~Day 29: Subject with Titer \>= 640p-value: 0.1284Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point.~Day 57: Subject with Titer \>= 40p-value: 1Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point.~Day 57: Subject with Titer\>=160p-value: 0.6411Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point.~Day 57: Subject with Titer\>=640p-value: 0.5382Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point.~Day 182: Subject with Titer \>= 40p-value: 0.4915Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point.~Day 182: Subject with Titer \>= 160p-value: >0.9999Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-Chikungunya neutralizing activity at or above selected thresholds by time point.~Day 182: Subject with Titer \>= 640p-value: 0.552Fisher Exact
Secondary
Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds
Evaluation of Anti-VEEV neutralizing antibody response, as determined by Plaque-Reduction Neutralization Test (PRNT80), via proportion of participants with titers of at least 40, 160 or 640 on Days 1, 22 and 29.
Time frame: Day 1, 22, 29
Population: Immunogenicity evaluable population. 11 alphavirus naïve participants were unable to attend their scheduled visit at Day 29.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Experimental: Prior Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 1 (Titer >=160) | 76.7 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 22 (Titer >=640) | 56.7 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 22 (Titer >=40) | 90.0 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 29 (Titer >=40) | 90.0 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 1 (Titer >=640) | 53.3 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 29 (Titer >=160) | 83.3 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 22 (Titer >=160) | 80.0 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 29 (Titer >=640) | 60.0 percentage of participants |
| Experimental: Prior Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 1 (Titer >=40) | 90.0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 29 (Titer >=640) | 0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 1 (Titer >=40) | 0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 1 (Titer >=160) | 0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 1 (Titer >=640) | 0.0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 22 (Titer >=40) | 0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 22 (Titer >=160) | 0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 22 (Titer >=640) | 0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 29 (Titer >=40) | 0 percentage of participants |
| Control: Naive Alpha | Percentage of Participants With Anti-VEEV PRNT Neutralizing Activity at or Above Selected Thresholds | Day 29 (Titer >=160) | 0 percentage of participants |
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-VEEV PRNT neutralizing activity at or above selected thresholds by time point.~Day 1: Subject with Titer \>= 40p-value: <0.0001Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-VEEV PRNT neutralizing activity at or above selected thresholds by time point.~Day 1: Subject with Titer \>= 160p-value: <0.0001Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-VEEV PRNT neutralizing activity at or above selected thresholds by time point.~Day 1: Subject with Titer \>= 640p-value: <0.0001Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-VEEV PRNT neutralizing activity at or above selected thresholds by time point.~Day 22: Subject with Titer \>= 40p-value: <0.0001Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-VEEV PRNT neutralizing activity at or above selected thresholds by time point.~Day 22: Subject with Titer \>= 160p-value: <0.0001Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-VEEV PRNT neutralizing activity at or above selected thresholds by time point.~Day 22: Subject with Titer \>=640p-value: <0.0001Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-VEEV PRNT neutralizing activity at or above selected thresholds by time point.~Day 29: Subject with Titer \>= 40p-value: <0.0001Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-VEEV PRNT neutralizing activity at or above selected thresholds by time point.~Day 29: Subjects with Titer \>= 160p-value: <0.0001Fisher Exact
Comparison: Null hypothesis for analysis of percentage of subjects with Anti-VEEV PRNT neutralizing activity at or above selected thresholds by time point.~Day 29 : Subjects with Titer \>=640p-value: <0.0001Fisher Exact