The clinical study will evaluate safety and the immune response of a prime- boost regimen with a live attenuated influenza vaccine (LAIV) prime and an inactivated split influenza vaccine (IIV) boost with or without adjuvant.
This is a prospective, multi-center, randomized, controlled, observer-blind, Phase 1 trial in healthy male and female adults 18 through 39 years of age to evaluate safety and the immune response of a prime boost regimen with LAIV prime and IIV boost with or without adjuvant. Participants will be randomized 4:3:1:3:2 to one of five groups to receive a first dose of study cH8/1N1 LAIV (or placebo) or study cH8/1N1 IIV + AS03A adjuvant (or placebo) followed three months later by study cH5/1N1 IIV +/- AS03A adjuvant (or placebo).
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
TRIPLE
Enrollment
65
Live-attenuated influenza virus vaccine (LAIV) expressing chimeric hemagglutinin (HA) with the H8 head and H1 stalk and neuraminidase (NA) subtype 1 (N1) (cH8/1N1): HA head, A/mallard/Sweden/24/2002 (H8N4); HA stalk, A/California/04/2009 (H1N1); NA, A/California/04/2009 (H1N1) containing the backbone of the cold-adapted/temperature sensitive of the Russian LAIV A/Leningrad/134/17/1957 (Len17 IDCDCRG46D). Administered intranasally as drops at a dose of 10⁷·⁵ (plus or minus ⁰·⁵) 50% egg infectious dose (EID50), formulated in a total volume of 0.5 mL sterile saline (0.25 mL per nostril).
Chimeric H5 head with H1 stalk plus N1 (cH5/1N1) split virion inactivated influenza virus vaccine (IIV) plus AS03 adjuvant: HA head, A/Vietnam/1203/2004 (H5N1); HA stalk, A/California/04/2009 (H1N1); NA, A/California/04/2009 (H1N1). Administered intramuscularly at a dose of 15 μg of hemagglutinin in a volume of 0.5 mL of phosphate buffered saline (PBS).
Duke University
Durham, North Carolina, United States
Cincinnati Children's Hospital Medical Center
Cincinnati, Ohio, United States
Number of Participants With Solicited Local Reactions Within 7 Days Following Each Vaccination
Solicited adverse events were assessed by study staff for 60 minutes after each vaccination and and then by study participants daily for 7 days on a a diary card. Solicited local reactions included: * Post LAIV dose: nasal congestion, rhinorrhea; * Post IIV dose: pain, redness, swelling.
Time frame: 7 days after each vaccination (Days 1-8 and Days 85-92)
Number of Participants With Solicited General Reactions Within 7 Days Following Each Vaccination
Solicited adverse events were assessed by study staff for 60 minutes after each vaccination and and then by study participants daily for 7 days on a a diary card. Solicited general reactions included: * abdominal pain * arthralgia * cough * diarrhea * fatigue * fever * headache * myalgia * nausea * shivering * sore throat * vomiting * wheezing
Time frame: 7 days after each vaccination (Days 1-8 and Days 85-92)
Number of Participants With Unsolicited Adverse Events Within 28 Days Following Any Vaccination
Unsolicited adverse events (AEs) are any AEs reported spontaneously by the participant, observed by the study personnel during study visits or those identified during review of medical records or source documents, such as diary cards. Participants were asked to record any unsolicited symptoms or other illness description in their diary card during the 28 days after each vaccination. All AEs, including clinical laboratory test results, were assessed by a study clinician and the study subject (as applicable) to quantify severity using a protocol-defined grading system as mild (mild symptoms, easily tolerated, not interfering with daily activities), moderate (causing some interference with daily activity), or severe (severe symptoms that prevent normal every day activities). The investigator assessed the relationship between study vaccines and the occurrence of each AE using clinical judgment.
Time frame: 28 days after each vaccination (Days 1 to 28 and Days 85 to 113)
Number of Participants With Grade 2 or Higher Hematological and Biochemical Laboratory Abnormalities From Day 8 to Day 113
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Chimeric H5 head with H1 stalk plus N1 (cH5/1N1) split virion inactivated influenza virus vaccine (IIV): HA head, A/Vietnam/1203/2004 (H5N1); HA stalk, A/California/04/2009 (H1N1); NA, A/California/04/2009 (H1N1). Administered intramuscularly at a dose of 15 μg of hemagglutinin in a volume of 0.5 mL of phosphate buffered saline (PBS).
Chimeric H8 head with H1 stalk plus N1 (cH8/1N1) inactivated influenza vaccine plus AS03 adjuvant: HA head, A/mallard/Sweden/24/2002 (H8N4); HA stalk, A/California/04/2009 (H1N1); NA, A/California/04/2009 (H1N1). Administered intramuscularly at a dose of 15 μg of hemagglutinin in a volume of 0.5 mL of phosphate buffered saline (PBS).
Administered intranasally as 0.25 mL nasal drops per nostril
Administered intramuscularly as 0.5 mL injection
Hematological and biochemical parameters assessed included hemoglobin, platelets, red blood cells, white blood cells (WBC), absolute neutrophil count (ANC), lymphocytes, monocytes, eosinophils, basophils, alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine, blood urea nitrogen (BUN) and BUN-to-creatinine ratio. Grading of laboratory parameters was based on the FDA Guidance for Industry: Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials as Grade 1 (Mild), Grade 2 (Moderate), Grade 3 (severe), or Grade 4 (Potentially life-threatening). Grade 2 or higher: * BUN: \> 26 mg/dL * Creatinine: \> 1.7 mg/dL * ALT, AST: \> 2.5 × upper limit of normal (ULN) * Hemoglobin: \< 11.0 g/dL (females) or \< 12.5 g/dL (males) or change from baseline \> 1.5 g/dL * WBC: \> 15,000 cell/mm³ or \< 2,500 cell/mm³ * Lymphocytes: \< 750 cell/mm³ * ANC: \< 1,500 cell/mm³ * Eosinophils: \> 1,500 cell/mm³ * Platelets: \< 125,000 cell/mm³
Time frame: Days 8, 29, 85, 92, and 113
Number of Participants With a Medically Attended Event (MAE), Laboratory-Confirmed Influenza-like Illness (LC-ILI), Potential Immune-mediated Disease (pIMD), or Serious Adverse Event (SAE) up to Day 113
An MAE is an event for which the participant received medical attention such as hospitalization, an emergency room visit, or a visit to or from medical personnel. pIMDs are a subset of AEs that include autoimmune diseases and other inflammatory and/or neurologic disorders of interest which may or may not have an autoimmune etiology. LC-ILI is defined as at least 1 systemic symptom (fever or myalgia) AND at least 1 respiratory symptom (cough or sore throat), confirmed by polymerase chain reaction (PCR) assay. An SAE is an AE that met any of the following: * Death * Life threatening * Required inpatient hospitalization or prolongation of existing hospitalization * Results in persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions * Results in congenital anomaly/birth defect * An important medical event that may jeopardize the well-being of the subject or require medical or surgical intervention to prevent an above outcome.
Time frame: Through Day 113 (28 days post-dose 2)
Number of Participants With Any Grade 2 or Higher Hematological and Biochemical Laboratory Abnormalities From Month 9 to Month 15
Hematological and biochemical parameters assessed included hemoglobin, platelets, red blood cells, white blood cells (WBC), absolute neutrophil count (ANC), lymphocytes, monocytes, eosinophils, basophils, alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine, blood urea nitrogen (BUN) and BUN-to-creatinine ratio. Grading of laboratory parameters was based on the FDA Guidance for Industry: Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials as Grade 1 (Mild), Grade 2 (Moderate), Grade 3 (severe), or Grade 4 (Potentially life-threatening). Grade 2 or higher: * BUN: \> 26 mg/dL * Creatinine: \> 1.7 mg/dL * ALT, AST: \> 2.5 × upper limit of normal (ULN) * Hemoglobin: \< 11.0 g/dL (females) or \< 12.5 g/dL (males) or change from baseline \> 1.5 g/dL * WBC: \> 15,000 cell/mm³ or \< 2,500 cell/mm³ * Lymphocytes: \< 750 cell/mm³ * ANC: \< 1,500 cell/mm³ * Eosinophils: \> 1,500 cell/mm³ * Platelets: \< 125,000 cell/mm³
Time frame: Month 9 (6 months post-dose 2) and Month 15 (12 months post-dose 2)
Number of Participants With a Medically Attended Event (MAE), Laboratory-Confirmed Influenza-like Illness (LC-ILI), Potential Immune-mediated Disease (pIMD), or Serious Adverse Event (SAE) up to End of Study
An MAE is an event for which the participant received medical attention such as hospitalization, an emergency room visit, or a visit to or from medical personnel. pIMDs are a subset of AEs that include autoimmune diseases and other inflammatory and/or neurologic disorders of interest which may or may not have an autoimmune etiology. LC-ILI is defined as at least 1 systemic symptom (fever or myalgia) AND at least 1 respiratory symptom (cough or sore throat), confirmed by PCR assay. An SAE is an AE that met any of the following: * Death * Life threatening * Required inpatient hospitalization or prolongation of existing hospitalization * Resulted in persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions * Resulted in congenital anomaly/birth defect * An important medical event that may jeopardize the well-being of the subject or require medical or surgical intervention to prevent an above outcome.
Time frame: From first dose to end of study, 588 days (21 months; 18 months post-dose 2)
Number of Participants in Groups 1, 2, and 3 With Detectable Influenza A Virus in Nasal and Oropharyngeal Swabs on Days 1 to 5
To detect viral shedding participants who received LAIV vaccine or intranasal sterile saline as the prime dose had nasal and oropharyngeal swabs collected on Days 1 to 5. Influenza type A virus ribonucleic acid (RNA) was detected using reverse transcription polymerase chain reaction (RT-PCR).
Time frame: Days 1 to 5
Number of Participants in Groups 1, 2, and 3 With Viable Vaccine Virus in Cell Culture Through 5 Days Post-vaccination
To study virus infectivity, nasal and oropharyngeal swab specimens that tested influenza A positive by RT-PCR were further tested for viability of virus in Madin Darby canine kidney (MDCK) cell culture and stained with monoclonal antibody specific to the cH8/1N1 LAIV virus to confirm detected virus is of vaccine origin.
Time frame: Days 1 to 5
Percentage of Participants With Serum Anti-H1 Hemagglutinin Stalk Immunoglobulin G Antibody Seropositivity
Anti-H1 hemagglutinin (HA) stalk immunoglobulin G (IgG) was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured IgG antibodies against the H1 stalk domain by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]) . Titers are expressed as ELISA units (EU) per mL and were calculated on the basis of an internal standard to which units were arbitrarily assigned. Seropositivity rate was defined as the percentage of participants with an antibody titer of at least the cut-off for the assay; ≥ 65.3 EU/mL.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), Month 9 (6 months post-dose 2), and Month 15 (12 months post-dose 2)
Geometric Mean Titer of Serum Anti-H1 Hemagglutinin Stalk IgG Antibodies
Anti-H1 hemagglutinin stalk immunoglobulin G (IgG) was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured IgG antibodies against the H1 stalk domain by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]) . Titers are expressed as ELISA units (EU) per mL and were calculated on the basis of an internal standard to which units were arbitrarily assigned. The lower limit of quantitation (LLOQ) for the assay was 65.3 EU/mL.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), Month 9 (6 months post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 4-fold Increase From Baseline in Serum Anti-H1 Hemagglutinin Stalk IgG Antibodies
Anti-H1 hemagglutinin stalk immunoglobulin G (IgG) was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured IgG antibodies against the H1 stalk domain by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]) .
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), Month 9 (6 months post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 10-fold Increase From Baseline in Serum Anti-H1 Hemagglutinin Stalk IgG Antibodies
Anti-H1 hemagglutinin stalk immunoglobulin G (IgG) was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured IgG antibodies against the H1 stalk domain by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]) .
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), Month 9 (6 months post-dose 2), and Month 15 (12 months post-dose 2)
Mean Geometric Increase From Baseline in Serum Anti-H1 Hemagglutinin Stalk IgG Antibodies
Anti-H1 hemagglutinin stalk immunoglobulin G (IgG) was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured IgG antibodies against the H1 stalk domain by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]). Mean geometric increase represents the fold-rise in antibody titer from baseline to each post-baseline time point (ratio of post-baseline titer to Baseline titer).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), Month 9 (6 months post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With Serum Anti-H1 Hemagglutinin Stalk Immunoglobulin A Antibody Seropositivity
Anti-H1 hemagglutinin stalk immunoglobulin A (IgA) was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured IgA antibodies against the H1 stalk domain by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]) . Seropositivity rate was defined as the percentage of participants with an antibody titer of at least the cut-off for the assay; ≥ 1:100.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Geometric Mean Titer of Serum Anti-H1 Hemagglutinin Stalk IgA Antibodies
Anti-H1 hemagglutinin stalk immunoglobulin A (IgA) was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured IgA antibodies against the H1 stalk domain by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]) .
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 4-fold Increase From Baseline in Serum Anti-H1 Hemagglutinin Stalk IgA Antibodies
Anti-H1 hemagglutinin stalk immunoglobulin A (IgA) was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured IgA antibodies against the H1 stalk domain by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]) .
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 10-fold Increase From Baseline in Serum Anti-H1 Hemagglutinin Stalk IgA Antibodies
Anti-H1 hemagglutinin stalk immunoglobulin A (IgA) was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured IgA antibodies against the H1 stalk domain by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]) .
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Mean Geometric Increase From Baseline in Serum Anti-H1 Hemagglutinin Stalk IgA Antibodies
Anti-H1 hemagglutinin stalk immunoglobulin A (IgA) was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured IgA antibodies against the H1 stalk domain by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]) . Mean geometric increase represents the fold-rise in antibody titer from baseline to each post-baseline time point (ratio of post-baseline titer to Baseline titer).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With Serum Anti-H1 Hemagglutinin Stalk Neutralizing Antibody Seropositivity
Anti H1 hemagglutinin stalk neutralizing antibodies were quantified using a microneutralization (MN) assay using a virus that expresses a chimeric hemagglutinin that contains an exotic HA head domain (strain A/mallard/Sweden/81/2002 \[H6N1\]) and the H1 stalk domain (strain A/California/04/2009 \[H1N1pandemic\]) and an exotic neuraminidase, N5, for which humans are generally naïve (strain: A/mallard/Sweden/86/2003 \[H12N5\]). Seropositivity rate was defined as the percentage of participants with an antibody titer of ≥ 1:10.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Geometric Mean Titer of Serum Anti-H1 Hemagglutinin Stalk Neutralizing Antibodies
Anti H1 hemagglutinin stalk neutralizing antibodies were quantified using a microneutralization (MN) assay using a virus that expresses a chimeric hemagglutinin that contains an exotic HA head domain (strain A/mallard/Sweden/81/2002 (\[H6N1\]) and the H1 stalk domain (strain A/California/04/2009 (\[H1N1pandemic\]) and an exotic neuraminidase, N5, for which humans are generally naïve (strain: A/mallard/Sweden/86/2003 \[H12N5\]). The LLOQ for the assay was 1:10.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 4-fold Increase From Baseline in Serum Anti-H1 Hemagglutinin Stalk Neutralizing Antibodies
Anti H1 hemagglutinin stalk neutralizing antibodies were quantified using a microneutralization (MN) assay using a virus that expresses a chimeric hemagglutinin that contains an exotic HA head domain (strain A/mallard/Sweden/81/2002 (\[H6N1\]) and the H1 stalk domain (strain A/California/04/2009 (\[H1N1pandemic\]) and an exotic neuraminidase, N5, for which humans are generally naïve (strain: A/mallard/Sweden/86/2003 \[H12N5\]).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 10-fold Increase From Baseline in Serum Anti-H1 Hemagglutinin Stalk Neutralizing Antibodies
Anti H1 hemagglutinin stalk neutralizing antibodies were quantified using a microneutralization (MN) assay using a virus that expresses a chimeric hemagglutinin that contains an exotic HA head domain (strain A/mallard/Sweden/81/2002 (\[H6N1\]) and the H1 stalk domain (strain A/California/04/2009 (\[H1N1pandemic\]) and an exotic neuraminidase, N5, for which humans are generally naïve (strain: A/mallard/Sweden/86/2003 \[H12N5\]).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Mean Geometric Increase From Baseline in Serum Anti-H1 Hemagglutinin Stalk Neutralizing Antibodies
Anti H1 hemagglutinin stalk neutralizing antibodies were quantified using a microneutralization (MN) assay using a virus that expresses a chimeric hemagglutinin that contains an exotic HA head domain (strain A/mallard/Sweden/81/2002 \[H6N1\]) and the H1 stalk domain (strain A/California/04/2009 \[H1N1pandemic\]) and an exotic neuraminidase, N5, for which humans are generally naïve (strain: A/mallard/Sweden/86/2003 \[H12N5\]). Mean geometric increase represents the fold-rise in antibody titer from baseline to each post-baseline time point (ratio of post-baseline titer to Baseline titer).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Serum Antibody-dependent Cell-mediated Cytotoxicity (ADCC) to the H1 Hemagglutinin Stalk
Antibody-dependent cell-mediated cytotoxicity (ADCC) is an immune response leading to lysis of antibody-coated target cells by immune effector cells and is triggered by the interaction between the Fc portion of an antibody and Fc-gamma receptors expressed on immune effector cells. This bioluminescent assay measured antibodies to a chimeric hemagglutinin (H6 head domain and H1 stalk domain) virus that mediate ADCC activity via the Fc-receptor. ADCC activity was measured in relative luciferase units (RLU) for serial dilutions of serum samples using a plate reader. ADCC activity was expressed by the area under the curve (AUC) of luminescence (RLU) per serial dilution (X-fold serial dilutions).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Fold-Increase From Baseline in Serum ADCC to the H1 Hemagglutinin Stalk
Antibody-dependent cell-mediated cytotoxicity (ADCC) is an immune response leading to lysis of antibody-coated target cells by immune effector cells and is triggered by the interaction between the Fc portion of an antibody and Fc-gamma receptors expressed on immune effector cells. This bioluminescent assay measured antibodies to a chimeric hemagglutinin (H6 head domain and H1 stalk domain) virus that mediate ADCC activity via the Fc-receptor. ADCC activity was measured by the area under the curve (AUC) of luminescence per serial dilution.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 4-fold Increase From Baseline in Serum ADCC to the H1 Hemagglutinin Stalk
Antibody-dependent cell-mediated cytotoxicity (ADCC) is an immune response leading to lysis of antibody-coated target cells by immune effector cells and is triggered by the interaction between the Fc portion of an antibody and Fc-gamma receptors expressed on immune effector cells. This bioluminescent assay measured antibodies to a chimeric hemagglutinin (H6 head domain and H1 stalk domain) virus that mediate ADCC activity via the Fc-receptor. ADCC activity was measured by the area under the curve (AUC) of luminescence per serial dilution.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 10-fold Increase From Baseline in Serum ADCC to the H1 Hemagglutinin Stalk
Antibody-dependent cell-mediated cytotoxicity (ADCC) is an immune response leading to lysis of antibody-coated target cells by immune effector cells and is triggered by the interaction between the Fc portion of an antibody and Fc-gamma receptors expressed on immune effector cells. This bioluminescent assay measured antibodies to a chimeric hemagglutinin (H6 head domain and H1 stalk domain) virus that mediate ADCC activity via the Fc-receptor. ADCC activity was measured by the area under the curve (AUC) of luminescence per serial dilution.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With Anti-H1 Hemagglutinin Stalk Salivary IgG Antibody Seropositivity
Anti-H1 hemagglutinin stalk immunoglobulin G (IgG) in saliva was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured IgG antibodies in saliva against the H1 stalk domain by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]). Seropositivity rate was defined as the percentage of participants with an antibody titer of at least the cut-off for the assay; ≥ 1:10.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Geometric Mean Titer of Anti-H1 Hemagglutinin Stalk Salivary IgG Antibodies
Anti-H1 hemagglutinin stalk immunoglobulin G (IgG) in saliva was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured IgG antibodies against the H1 stalk domain by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]). The LLOQ for the assay was 1:10.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 4-fold Increase From Baseline in Anti-H1 Hemagglutinin Stalk Salivary IgG
Anti-H1 hemagglutinin stalk immunoglobulin G (IgG) in saliva was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured IgG antibodies in saliva against the H1 stalk domain by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 10-fold Increase From Baseline in Anti-H1 Hemagglutinin Stalk Salivary IgG
Anti-H1 hemagglutinin stalk immunoglobulin G (IgG) in saliva was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured IgG antibodies in saliva against the H1 stalk domain by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Mean Geometric Increase of Anti-H1 Hemagglutinin Stalk Salivary IgG Antibodies
Anti-H1 hemagglutinin stalk immunoglobulin G (IgG) in saliva was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured IgG antibodies in saliva against the H1 stalk domain by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]). Mean geometric increase represents the fold-rise in antibody titer from baseline to each post-baseline time point (ratio of post-baseline titer to Baseline titer).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With Anti-H1 Hemagglutinin Stalk Secretory IgA Antibody Seropositivity in Saliva
Anti-H1 hemagglutinin stalk secretory immunoglobulin A (IgA) in saliva was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured secretory IgA antibodies antibodies (actively secreted in the mucosa) against the H1 stalk domain in saliva using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]). Seropositivity rate was defined as the percentage of participants with an antibody titer of at least the cut-off for the assay; ≥ 1:4.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Geometric Mean Titer of Anti-H1 Hemagglutinin Stalk Secretory IgA Antibodies in Saliva
Anti-H1 hemagglutinin stalk secretory immunoglobulin A (IgA) in saliva was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured secretory IgA antibodies antibodies (actively secreted in the mucosa) against the H1 stalk domain in saliva using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]). The LLOQ for the assay was 1:4.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 4-fold Increase From Baseline in Anti-H1 Hemagglutinin Stalk Secretory IgA Antibodies in Saliva
Anti-H1 hemagglutinin stalk secretory immunoglobulin A (IgA) in saliva was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured secretory IgA antibodies (actively secreted in the mucosa) against the H1 stalk domain in saliva by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 10-fold Increase From Baseline in Anti-H1 Hemagglutinin Stalk Secretory IgA Antibodies in Saliva
Anti-H1 hemagglutinin stalk secretory immunoglobulin A (IgA) in saliva was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured secretory IgA antibodies (actively secreted in the mucosa) against the H1 stalk domain in saliva by using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Mean Geometric Increase From Baseline in Anti-H1 Hemagglutinin Stalk Secretory IgA in Saliva
Anti-H1 hemagglutinin stalk secretory immunoglobulin A (IgA) in saliva was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured secretory IgA antibodies antibodies (actively secreted in the mucosa) against the H1 stalk domain in saliva using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]). Mean geometric increase represents the fold-rise in antibody titer from Baseline to each post-baseline time point (ratio of post-baseline titer to Baseline titer).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With Anti-H1 Hemagglutinin Stalk Total IgA Antibody Seropositivity in Saliva
Anti-H1 hemagglutinin stalk total immunoglobulin A (IgA) in saliva was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured total IgA antibodies antibodies (secreted through active and passive transfer processes in the mucosa) against the H1 stalk domain in saliva using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]). Seropositivity rate was defined as the percentage of participants with an antibody titer of at least the cut-off for the assay; ≥ 1:10.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Geometric Mean Titer of Anti-H1 Hemagglutinin Stalk Total IgA Antibodies in Saliva
Anti-H1 hemagglutinin stalk total immunoglobulin A (IgA) in saliva was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured total IgA antibodies antibodies (secreted through active and passive transfer processes in the mucosa) against the H1 stalk domain in saliva using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]). The LLOQ for the assay was 1:10.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 4-fold Increase From Baseline in Anti-H1 Hemagglutinin Stalk Total IgA Antibodies in Saliva
Anti-H1 hemagglutinin stalk total immunoglobulin A (IgA) in saliva was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured total IgA antibodies antibodies (secreted through active and passive transfer processes in the mucosa) against the H1 stalk domain in saliva using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 10-fold Increase From Baseline in Anti-H1 Hemagglutinin Stalk Total IgA Antibodies in Saliva
Anti-H1 hemagglutinin stalk total immunoglobulin A (IgA) in saliva was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured total IgA antibodies antibodies (secreted through active and passive transfer processes in the mucosa) against the H1 stalk domain in saliva using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Mean Geometric Increase From Baseline in Anti-H1 Hemagglutinin Stalk Total IgA Antibodies in Saliva
Anti-H1 hemagglutinin stalk total immunoglobulin A (IgA) in saliva was quantified using an enzyme-linked immunosorbent assay (ELISA). The ELISA measured total IgA antibodies (secreted through active and passive transfer processes in the mucosa) against the H1 stalk domain in saliva using a chimeric protein containing an exotic H6 hemagglutinin head domain that the vaccinees have not previously been exposed to (strain A/mallard/Sweden/81/02 \[H6N1\]) and the same H1 stalk domain as expressed by the vaccine (strain A/California/04/09 \[H1N1\]). Mean geometric increase represents the fold-rise in antibody titer from baseline to each post-baseline time point (ratio of post-baseline titer to Baseline titer).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With Serum Anti-H2 Full-length Hemagglutinin IgG Antibody Seropositivity
To determine antibody breadth, assays were performed to measure the induction of cross-reactive IgG antibodies to a Group 1 influenza A virus with a heterosubtypic hemagglutinin, subtype H2, of which the stalk domain shares about 78% amino acid identity with the H1 vaccine stalk domain. Anti-H2 full-length (ecto-domain) hemagglutinin IgG was quantified by ELISA using a recombinant antigen based on A/mallard/Netherlands/5/1999 (H2N9) HA. Titers are expressed as ELISA units (EU) per mL and were calculated on the basis of an internal standard to which units were arbitrarily assigned. Seropositivity rate was defined as the percentage of participants with an antibody titer of at least the cut-off for the assay; ≥ 22.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Geometric Mean Titer of Serum Anti-H2 Full-length Hemagglutinin IgG Antibodies
To determine antibody breadth, assays were performed to measure the induction of cross-reactive IgG antibodies to a Group 1 influenza A virus with a heterosubtypic hemagglutinin, subtype H2, of which the stalk domain shares about 78% amino acid identity with the H1 vaccine stalk domain. Anti-H2 full-length (ecto-domain) hemagglutinin IgG was quantified by ELISA using a recombinant antigen based on A/mallard/Netherlands/5/1999 (H2N9) HA. Titers are expressed as ELISA units (EU) per mL and were calculated on the basis of an internal standard to which units were arbitrarily assigned.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 4-fold Increase From Baseline in Serum Anti-H2 Full-length Hemagglutinin IgG Antibodies
To determine antibody breadth, assays were performed to measure the induction of cross-reactive IgG antibodies to a Group 1 influenza A virus with a heterosubtypic hemagglutinin, subtype H2, of which the stalk domain shares about 78% amino acid identity with the H1 vaccine stalk domain. Anti-H2 full-length (ecto-domain) hemagglutinin IgG was quantified by ELISA using a recombinant antigen based on A/mallard/Netherlands/5/1999 (H2N9) HA.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 10-fold Increase From Baseline in Serum Anti-H2 Full-length Hemagglutinin IgG Antibodies
To determine antibody breadth, assays were performed to measure the induction of cross-reactive IgG antibodies to a Group 1 influenza A virus with a heterosubtypic hemagglutinin, subtype H2, of which the stalk domain shares about 78% amino acid identity with the H1 vaccine stalk domain. Anti-H2 full-length (ecto-domain) hemagglutinin IgG was quantified by ELISA using a recombinant antigen based on A/mallard/Netherlands/5/1999 (H2N9) HA.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Mean Geometric Increase of Serum Anti-H2 Full-length Hemagglutinin IgG Antibodies
To determine antibody breadth, assays were performed to measure the induction of cross-reactive IgG antibodies to a Group 1 influenza A virus with a heterosubtypic hemagglutinin, subtype H2, of which the stalk domain shares about 78% amino acid identity with the H1 vaccine stalk domain. Anti-H2 full-length (ecto-domain) hemagglutinin IgG was quantified by ELISA using a recombinant antigen based on A/mallard/Netherlands/5/1999 (H2N9) HA. Mean geometric increase represents the fold-rise in antibody titer from Baseline to each post-baseline time point (ratio of post-baseline titer to Baseline titer).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With Serum Anti-H9 Full-length Hemagglutinin IgG Antibody Seropositivity
To determine antibody breadth, assays were performed to measure the induction of cross-reactive IgG antibodies to a Group 1 influenza A virus with a heterosubtypic hemagglutinin, subtype H9, the stalk domain of which shares about 59% amino acid identity with the H1 vaccine stalk domain. Anti-H9 full-length (ecto-domain) hemagglutinin IgG was quantified by ELISA using a recombinant antigen based on Strain A/chicken/Hong Kong/G9/1997 (H9N2) HA. Titers are expressed as ELISA units (EU) per mL and were calculated on the basis of an internal standard to which units were arbitrarily assigned. Seropositivity rate was defined as the percentage of participants with an antibody titer of at least the cut-off for the assay; ≥ 31.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Geometric Mean Titer of Serum Anti-H9 Full-length Hemagglutinin IgG Antibodies
To determine antibody breadth, assays were performed to measure the induction of cross-reactive IgG antibodies to a Group 1 influenza A virus with a heterosubtypic hemagglutinin, subtype H9, the stalk domain of which shares about 59% amino acid identity with the H1 vaccine stalk domain. Anti-H9 full-length (ecto-domain) hemagglutinin IgG was quantified by ELISA using a recombinant antigen based on Strain A/chicken/Hong Kong/G9/1997 (H9N2) HA. Titers are expressed as ELISA units (EU) per mL and were calculated on the basis of an internal standard to which units were arbitrarily assigned. The LLOQ for the assay was 31 EU/mL.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 4-fold Increase From Baseline in Serum Anti-H9 Full-length Hemagglutinin IgG Antibodies
To determine antibody breadth, assays were performed to measure the induction of cross-reactive IgG antibodies to a Group 1 influenza A virus with a heterosubtypic hemagglutinin, subtype H9, the stalk domain of which shares about 59% amino acid identity with the H1 vaccine stalk domain. Anti-H9 full-length (ecto-domain) hemagglutinin IgG was quantified by ELISA using a recombinant antigen based on Strain A/chicken/Hong Kong/G9/1997 (H9N2) HA.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 10-fold Increase From Baseline in Serum Anti-H9 Full-length Hemagglutinin IgG Antibodies
To determine antibody breadth, assays were performed to measure the induction of cross-reactive IgG antibodies to a Group 1 influenza A virus with a heterosubtypic hemagglutinin, subtype H9, the stalk domain of which shares about 59% amino acid identity with the H1 vaccine stalk domain. Anti-H9 full-length(ecto-domain) hemagglutinin IgG was quantified by ELISA using a recombinant antigen based on Strain A/chicken/Hong Kong/G9/1997 (H9N2) HA.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Mean Geometric Increase of Serum Anti-H9 Full-length Hemagglutinin IgG Antibodies
To determine antibody breadth, assays were performed to measure the induction of cross-reactive IgG antibodies to a Group 1 influenza A virus with a heterosubtypic hemagglutinin, subtype H9, the stalk domain of which shares about 59% amino acid identity with the H1 vaccine stalk domain. Anti-H9 full-length (ecto-domain) hemagglutinin IgG was quantified by ELISA using a recombinant antigen based on Strain A/chicken/Hong Kong/G9/1997 (H9N2) HA. Mean geometric increase represents the fold-rise in antibody titer from Baseline to each post-baseline time point (ratio of post-baseline titer to Baseline titer).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With Serum Anti-H18 Full-length Hemagglutinin IgG Antibody Seropositivity
To determine antibody breadth, assays were performed to measure the induction of cross-reactive IgG antibodies to a Group 1 influenza A virus with a heterosubtypic hemagglutinin distantly related to the currently circulating influenza A/H1 viruses, subtype H18, the stalk domain of which shares about 65% amino acid identity with the H1 vaccine stalk domain. Anti-H18 full-length (ecto-domain) hemagglutinin IgG was quantified by ELISA using a recombinant antigen based on Strain A/flat-faced bat/Peru/033/10 (H18N11) HA. Titers are expressed as ELISA units (EU) per mL and were calculated on the basis of an internal standard to which units were arbitrarily assigned. Seropositivity rate was defined as the percentage of participants with an antibody titer of at least the cut-off for the assay; ≥ 42.3.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Geometric Mean Titer of Serum Anti-H18 Full-length Hemagglutinin IgG Antibodies
To determine antibody breadth, assays were performed to measure the induction of cross-reactive IgG antibodies to a Group 1 influenza A virus with a heterosubtypic hemagglutinin distantly related to the currently circulating influenza A/H1 viruses, H18, the stalk domain of which shares about 65% amino acid identity with the H1 vaccine stalk domain. Anti-H18 full-length (ecto-domain) hemagglutinin IgG was quantified by ELISA using a recombinant antigen based on Strain A/flat-faced bat/Peru/033/10 (H18N11) HA. Titers are expressed as ELISA units (EU) per mL and were calculated on the basis of an internal standard to which units were arbitrarily assigned.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 4-fold Increase From Baseline in Serum Anti-H18 Full-length Hemagglutinin IgG Antibodies
To determine antibody breadth, assays were performed to measure the induction of cross-reactive IgG antibodies to a Group 1 influenza A virus with a heterosubtypic hemagglutinin distantly related to the currently circulating influenza A/H1 viruses, subtype H18, the stalk domain of which shares about 65% amino acid identity with the H1 vaccine stalk domain. Anti-H18 full-length (ecto-domain) hemagglutinin IgG was quantified by ELISA using a recombinant antigen based on Strain A/flat-faced bat/Peru/033/10 (H18N11) HA.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 10-fold Increase From Baseline in Serum Anti-H18 Full-length Hemagglutinin IgG Antibodies
To determine antibody breadth, assays were performed to measure the induction of cross-reactive IgG antibodies to a Group 1 influenza A virus with a heterosubtypic hemagglutinin distantly related to the currently circulating influenza A/H1 viruses, subtype H18, the stalk domain of which shares about 65% amino acid identity with the H1 vaccine stalk domain. Anti-H18 full-length (ecto-domain) hemagglutinin IgG was quantified by ELISA using a recombinant antigen based on Strain A/flat-faced bat/Peru/033/10 (H18N11) HA.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Mean Geometric Increase of Serum Anti-H18 Full-length Hemagglutinin IgG Antibodies
To determine antibody breadth, assays were performed to measure the induction of cross-reactive IgG antibodies to a Group 1 influenza A virus with a heterosubtypic hemagglutinin distantly related to the currently circulating influenza A/H1 viruses, subtype H18, the stalk domain of which shares about 65% amino acid identity with the H1 vaccine stalk domain. Anti-H18 full-length (ecto-domain) hemagglutinin IgG was quantified by ELISA using a recombinant antigen based on Strain A/flat-faced bat/Peru/033/10 (H18N11) HA. Mean geometric increase represents the fold-rise in antibody titer from Baseline to each post-baseline time point (ratio of post-baseline titer to Baseline titer).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With Serum Anti-Human H1N1 Virus Neutralizing Antibody Seropositivity
This assay was performed to measure the neutralizing potential of antibodies against the currently circulating human H1N1 isolate which is similar to the stalk used in study vaccines. Anti-human H1N1 virus neutralizing antibodies were quantified using a microneutralization (MN) assay using Strain A/Singapore/GP1908/2015 (IVR-180). Seropositivity rate was defined as the percentage of participants with an antibody titer of ≥ 1:10.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Geometric Mean Titer of Serum Anti-Human H1N1 Virus Neutralizing Antibodies
This assay was performed to measure the neutralizing potential of antibodies against the currently circulating human H1N1 isolate which is similar to the stalk used in study vaccines. Anti-human H1N1 virus neutralizing antibodies were quantified using a microneutralization (MN) assay using Strain A/Singapore/GP1908/2015 (IVR-180). The LLOQ for the assay was 1:10.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 4-fold Increase in Serum Anti-Human H1N1 Virus Neutralizing Antibodies
This assay was performed to measure the neutralizing potential of antibodies against the currently circulating human H1N1 isolate which is similar to the stalk used in study vaccines. Anti-human H1N1 virus neutralizing antibodies were quantified using a microneutralization (MN) assay using Strain A/Singapore/GP1908/2015 (IVR-180).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 10-fold Increase From Baseline in Serum Anti-Human H1N1 Virus Neutralizing Antibodies
This assay was performed to measure the neutralizing potential of antibodies against the currently circulating human H1N1 isolate which is similar to the stalk used in study vaccines. Anti-human H1N1 virus neutralizing antibodies were quantified using a microneutralization (MN) assay using Strain A/Singapore/GP1908/2015 (IVR-180).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Mean Geometric Increase of Serum Anti-Human H1N1 Virus Neutralizing Antibodies
This assay was performed to measure the neutralizing potential of antibodies against the currently circulating human H1N1 isolate which is similar to the stalk used in study vaccines. Anti-human H1N1 virus neutralizing antibodies were quantified using a microneutralization (MN) assay using Strain A/Singapore/GP1908/2015 (IVR-180). Mean geometric increase represents the fold-rise in antibody titer from Baseline to each post-baseline time point (ratio of post-baseline titer to Baseline titer).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With Serum Anti-Avian-Swine H1N1 Virus Neutralizing Antibody Seropositivity
This assay was performed to measure the neutralizing potential of cross-reactive antibodies to a Group 1 influenza against an H1N1 virus isolate that currently circulates in animals and is antigenically different from current human isolates. Anti-avian-swine H1N1 virus neutralizing antibodies were quantified using a microneutralization (MN) assay using Strain A/Swine/Jiangsu/40/2011 (asH1N1). Seropositivity rate was defined as the percentage of participants with an antibody titer of ≥ 1:10.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Geometric Mean Titer of Serum Anti-Avian-Swine H1N1 Virus Neutralizing Antibodies
This assay was performed to measure the neutralizing potential of cross-reactive antibodies to a Group 1 influenza against an H1N1 virus isolate that currently circulates in animals and is antigenically different from current human isolates. Anti-avian-swine H1N1 virus neutralizing antibodies were quantified using a microneutralization (MN) assay using Strain A/Swine/Jiangsu/40/2011 (asH1N1). The LLOQ for the assay was 1:10.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 4-fold Increase in Serum Anti-Avian-Swine H1N1 Virus Neutralizing Antibodies
This assay was performed to measure the neutralizing potential of cross-reactive antibodies to a Group 1 influenza against an H1N1 virus isolate that currently circulates in animals and is antigenically different from current human isolates. Anti-avian-swine H1N1 virus neutralizing antibodies were quantified using a microneutralization (MN) assay using Strain A/Swine/Jiangsu/40/2011 (asH1N1).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 10-fold Increase in Serum Anti-Avian-Swine H1N1 Virus Neutralizing Antibodies
This assay was performed to measure the neutralizing potential of cross-reactive antibodies to a Group 1 influenza against an H1N1 virus isolate that currently circulates in animals and is antigenically different from current human isolates. Anti-avian-swine H1N1 virus neutralizing antibodies were quantified using a microneutralization (MN) assay using Strain A/Swine/Jiangsu/40/2011 (asH1N1).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Mean Geometric Increase From Baseline in Serum Anti-Avian-Swine H1N1 Virus Neutralizing Antibodies
This assay was performed to measure the neutralizing potential of cross-reactive antibodies to a Group 1 influenza against an H1N1 virus isolate that currently circulates in animals and is antigenically different from current human isolates. Anti-avian-swine H1N1 virus neutralizing antibodies were quantified using a microneutralization (MN) assay using Strain A/Swine/Jiangsu/40/2011 (asH1N1). Mean geometric increase represents the fold-rise in antibody titer from Baseline to each post-baseline time point (ratio of post-baseline titer to Baseline titer).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With Serum Anti-H5N8 Virus Neutralizing Antibody Seropositivity
This assay was performed to measure the induction of antibodies reactive against the head domain of a group 1 influenza virus with a heterosubtypic hemagglutinin from a recent avian influenza virus. Anti-H5N8 virus neutralizing antibodies were quantified using a microneutralization (MN) assay using a reverse genetics (RG) reassortant virus based on Puerto Rico (PR)/8 for 6 genes with 2 surface proteins: HA and neuraminidase (NA) from A/Gyrfalcon/Washington/41088-6/2014 (H5N8). Seropositivity rate was defined as the percentage of participants with an antibody titer of ≥ 1:10.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Geometric Mean Titer of Serum Anti-H5N8 Virus Neutralizing Antibodies
This assay was performed to measure the induction of antibodies reactive against the head domain of a group 1 influenza virus with a heterosubtypic hemagglutinin from a recent avian influenza virus. Anti-H5N8 virus neutralizing antibodies were quantified using a microneutralization (MN) assay using a reverse genetics (RG) reassortant virus based on PR8 for 6 genes with 2 surface proteins: HA and NA from A/Gyrfalcon/Washington/41088-6/2014 (H5N8). The LLOQ for the assay was 1:10.
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 4-fold Increase in Serum Anti-H5N8 Virus Neutralizing Antibodies
This assay was performed to measure the induction of antibodies reactive against the head domain of a group 1 influenza virus with a heterosubtypic hemagglutinin from a recent avian influenza virus. Anti-H5N8 virus neutralizing antibodies were quantified using a microneutralization (MN) assay using a reverse genetics (RG) reassortant virus based on PR8 for 6 genes with 2 surface proteins: HA and NA from A/Gyrfalcon/Washington/41088-6/2014 (H5N8).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Percentage of Participants With a ≥ 10-fold Increase in Serum Anti-H5N8 Virus Neutralizing Antibodies
This assay was performed to measure the induction of antibodies reactive against the head domain of a group 1 influenza virus with a heterosubtypic hemagglutinin from a recent avian influenza virus. Anti-H5N8 virus neutralizing antibodies were quantified using a microneutralization (MN) assay using a reverse genetics (RG) reassortant virus based on PR8 for 6 genes with 2 surface proteins: HA and NA from A/Gyrfalcon/Washington/41088-6/2014 (H5N8).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)
Mean Geometric Increase From Baseline in Serum Anti-H5N8 Virus Neutralizing Antibodies
This assay was performed to measure the induction of antibodies reactive against the head domain of a group 1 influenza virus with a heterosubtypic hemagglutinin from a recent avian influenza virus. Anti-H5N8 virus neutralizing antibodies were quantified using a microneutralization (MN) assay using a reverse genetics (RG) reassortant virus based on PR8 for 6 genes with 2 surface proteins: HA and NA from A/Gyrfalcon/Washington/41088-6/2014 (H5N8). Mean geometric increase represents the fold-rise in antibody titer from Baseline to each post-baseline time point (ratio of post-baseline titer to Baseline titer).
Time frame: Baseline (pre-dose 1), Month 1 (28 days post-dose 1), Month 4 (28 days post-dose 2), and Month 15 (12 months post-dose 2)