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A Safety and Immunogenicity Study of IVACFLU-A/H5N1

A Phase 2/3 Double Blinded, Randomized, Placebo-controlled Study in Healthy Adult Volunteers in Vietnam to Examine the Safety and Immunogenicity of an Inactivated A/H5N1 Influenza Vaccine (IVACFLU-A/H5N1) Produced by IVAC

Status
Completed
Phases
Phase 2Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02612909
Enrollment
930
Registered
2015-11-24
Start date
2017-03-07
Completion date
2017-08-30
Last updated
2019-05-21

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Avian Influenza

Keywords

Avian Influenza, A/H5N1 vaccine, IVAC

Brief summary

The study hypothesis was that two 0.5 mL doses of whole virion monovalent A/H5N1 influenza vaccine (IVACFLU-A/H5N1) adjuvanted with alum would be safe and well tolerated in healthy adults, and that at least one of the two doses tested would be immunogenic in 60% or more of the subjects tested.

Detailed description

Although the A/H1N1 (2009) pandemic has subsided and the virus has become endemic, the threat of another pandemic due to avian influenza A/H5N1 remains constant. Since 1997, highly pathogenic A/H5N1 avian viruses have caused both widespread outbreaks in poultry with high mortality and sporadic, severe, and fatal disease in humans. Southeast Asian countries, including Vietnam, have been affected by influenza A/H5N1. From 2003 through March 2015, WHO has reported 826 confirmed human cases of A/H5N1 influenza infection; including 440 fatal cases (World Health Organization, 2015). Southeast Asian countries accounted for 42% of all confirmed influenza A/H5N1 cases reported since 2003, and influenza A/H5N1 infection in animals is now thought to be endemic in the region (World Health Organization, 2015). As of March 2015, Vietnam has reported 127 confirmed human cases and 64 deaths. In 2014, two cases of A/H5N1 avian influenza were reported in Vietnam. Therefore, the risk of transmission to human is still present. At the time of the study, no influenza A/H5N1 vaccine had been licensed in Vietnam. IVACFLU-A/H5N1 is an influenza A/H5N1 vaccine produced by Institute of Vaccines and Medical Biologicals (IVAC) using embryonated chicken eggs. IVACFLU-A/H5N1 is a whole virus vaccine, collected in a linear sucrose density gradient solution using a continuous flow centrifuge (Alfa Wassermann, West Caldwell, NJ) and inactivated with formaldehyde. The vaccine is alum adjuvanted. Vaccine strain NIBRG-14 derived from original influenza A/Vietnam/1194/2004 was provided to IVAC by the National Institute for Biological Standards and Control of the Health Protection Agency of the United Kingdom. A clinical trial of IVACFLU-A/H5N1 vaccine conducted in 75 subjects at the Ben Luc Health District in Vietnam in 2014 showed that the vaccine is safe and immunogenic at doses of 7.5 and 15 mcg. This study was conducted in two stages: Phase 2 was a dose selection study where subjects were randomized to one of the three groups (15 mcg IVACFLU-A/H5N1 vaccine, 30 mcg IVACFLU-A/H5N1 vaccine or placebo) at a 1:1:1 ratio. The conduct of Phase 3 was dependent on showing hemagglutination inhibition (HAI) response titer of ≥1:40 in ≥60% of vaccine recipients in at least one of the two Phase 2 IVACFLU-A/H5N1 vaccine groups. Based on the review of immunogenicity and safety results from the Phase 2 study, a dose of study vaccine was selected for Phase 3. Subjects were randomized at two sites (Khanh Hoa and Hai Phong) to receive the IVACFLU-A/H5N1 vaccine dose selected in Phase 2 or placebo . Safety was assessed in all subjects and immunogenicity was measured in a subset of subjects at the Hai Phong study site.

Interventions

BIOLOGICALIVACFLU-A/H5N1 vaccine

Monovalent A/H5N1 influenza vaccine (MIV), whole virion inactivated, purified by sucrose gradient on ultracentrifuge. The vaccine was produced in eggs, inactivated with formaldehyde, and formulated with aluminum hydroxide 0.6 mg/0.5 mL with no preservative.

BIOLOGICALPlacebo

Includes 4.500mg sodium chloride, 0.685 mg sodium phosphate dibasic dihydrate, and 0.186 mg sodium phosphate monobasic dihydrate.

Sponsors

National Institute of Hygiene and Epidemiology, Vietnam
CollaboratorOTHER
World Health Organization
CollaboratorOTHER
Department of Health and Human Services
CollaboratorFED
PATH
CollaboratorOTHER
FHI 360
CollaboratorOTHER
Institute of Vaccines and Medical Biologicals, Vietnam
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
Yes

Inclusion criteria

* Male or female adult 18 through 60 years of age at the enrollment visit. * Literate (by self-report) and willing to provide written informed consent. * Healthy adults, as established by the medical history and screening evaluations, including physical examination, capable and willing to complete Diary Cards, and willing to return for all follow-up visits. * For females able to become pregnant, willing to utilize reliable birth control measures (intrauterine device, hormonal contraception, condoms) through the Day 43 visit.

Exclusion criteria

* Participation in another clinical trial involving any vaccine or therapy within the previous three months, or planned enrollment in such a trial during the period of this study. * Received any non-study vaccine within 4 weeks prior to enrollment or refused to postpone receipt of such vaccines until after the Day 43 visit. * Current or recent (within 2 weeks of enrollment) acute illness with or without fever. * Received immune globulin or other blood products within 3 months prior to study enrollment or planned receipt of such products prior to the Day 43 visit. * Chronic administration (defined as more than 14 consecutively-prescribed days) of immunosuppressants or other immune-modulating therapy within six months prior to study enrollment. (For corticosteroids, this meant prednisone or equivalent, 0.5 mg per kg per day; topical or intranasal steroids were allowed.) * History of asthma. * Hypersensitivity after previous administration of any vaccine. * Suspected or known hypersensitivity to any of the study vaccine components, including chicken or egg protein, antibiotics, and rubber (from the vaccine vial stoppers). * Acute or chronic clinically significant pulmonary, cardiovascular, hepatobiliary, metabolic, neurologic, psychiatric, or renal functional abnormality, as determined by medical history, physical examination, or clinical laboratory screening tests (Phase 2 only), which in the opinion of the investigator, might have interfered with the study objectives. * History of any blood or solid organ cancer. * History of thrombocytopenic purpura or known bleeding disorder. * History of seizures. * Known or suspected immunosuppressed or immune deficient condition of any kind. * Known Hepatitis B Virus (HBV) or Hepatitis C virus (HCV) infection by self-report (Phase 3) or a positive test for either HBV surface antigen (HBsAg) or HCV antibody using anti-HCV test (Phase 2). * Known HIV infection (self-report) * Known active tuberculosis or symptoms of active tuberculosis (self-report). * History of chronic alcohol abuse and/or illegal drug use. * Pregnancy or lactation (a negative pregnancy test was required before administration of study product for all women of childbearing potential). * History of Guillain-Barre Syndrome. * Any condition in the opinion of the investigator that would have increased the health risk of the subject if he/she participated in the study or interfered with the evaluation of the study objectives. Note: Minor out-of-range laboratory values no greater than Grade 1 were not considered to be exclusionary at screening.

Design outcomes

Primary

MeasureTime frameDescription
Number and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 1, Day 43Serum specimens were tested for the presence of HAI antibodies to influenza. The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.

Secondary

MeasureTime frameDescription
Phase 2: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Hemagglutination Inhibition (HAI) TiterDay 22, Day 43Serum specimens were tested for the presence of HAI antibodies to influenza on day 1, day 22, and day 43 (day 1 and 22 prior to injection). The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.
Phase 3: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Hemagglutination Inhibition (HAI) TiterDay 43Serum specimens were tested for the presence of HAI antibodies to influenza. The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.
Phase 2: Geometric Mean Hemagglutination Inhibition (HAI) TiterDay 1, Day 22, Day 43Serum specimens were tested for the presence of HAI antibodies to influenza on day 1, day 22, and day 43 (day 1 and 22 prior to injection). The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.
Phase 3: Geometric Mean Hemagglutination Inhibition (HAI) TiterDay 1, Day 43Serum specimens were tested for the presence of HAI antibodies to influenza. The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.
Phase 2: Geometric Mean Hemagglutination Inhibition (HAI) Titer Ratio, With Respect to Day 1Day 22, Day 43Serum specimens were tested for the presence of HAI antibodies to influenza on day 1, day 22, and day 43 (day 1 and 22 prior to injection). The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.
Phase 3: Geometric Mean Hemagglutination Inhibition (HAI) Titer Ratio, With Respect to Day 1Day 43Serum specimens were tested for the presence of HAI antibodies to influenza. The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.
Number and Percentage of Subjects Experiencing Reactogenicity30 minutes after each injectionImmediate reactogenicity (30 minutes post-injection) were evaluated on Day 1 and Day 22 and consisted of: * Inspection of the upper arms for the presence or absence of redness, swelling, hardness, pain, or tenderness; and * Documentation of the presence or absence of headache, fever, fatigue/malaise, muscle aches, joint aches, nausea, vomiting, or chills. Immediate reactogenicity were assessed by a study physician or appropriately trained medical staff.
Phase 2: Number and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 1, Day 22Serum specimens were tested for the presence of HAI antibodies to influenza. The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.
Number and Percentage of Subjects Experiencing Unsolicited Serious Adverse Events (SAE)90 daysDefined as an adverse event that led to death, was life-threatening (subject at immediate risk of death); required inpatient hospitalization or prolongation of existing hospitalization; resulted in congenital anomaly/birth defect; resulted in a persistent or significant disability or incapacity.
Phase 2: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Neutralizing Antibody TiterDay 22, Day 43The microneutralization (MN) assay is an alternative assay for determining immunologic response to vaccination. It is a highly sensitive assay that can provide information on the ability of induced antibody to neutralize influenza virus. Titers of neutralizing antibodies were expressed as the amount of the greatest dilution of serum giving a neutralization of 50% of tissue cytopathic effects of the virus in the tissue culture.
Phase 3: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Neutralizing Antibody TiterDay 43The MN assay is an alternative assay for determining immunologic response to vaccination. It is a highly sensitive assay that can provide information on the ability of induced antibody to neutralize influenza virus. Titers of neutralizing antibodies were expressed as the amount of the greatest dilution of serum giving a neutralization of 50% of tissue cytopathic effects of the virus in the tissue culture. In Phase 3, MN assay was conducted in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in order to have at least 200 evaluable subjects receiving IVACFLU A/H5N1 and 40 evaluable subjects receiving placebo.
Phase 2: Geometric Mean Neutralizing Antibody TiterDay 1, Day 22, Day 43The microneutralization (MN) assay is an alternative assay for determining immunologic response to vaccination. It is a highly sensitive assay that can provide information on the ability of induced antibody to neutralize influenza virus. Titers of neutralizing antibodies were expressed as the amount of the greatest dilution of serum giving a neutralization of 50% of tissue cytopathic effects of the virus in the tissue culture.
Phase 3: Geometric Mean Neutralizing Antibody TiterDay 1, Day 43Serum specimens were tested for the presence of HAI antibodies to influenza. The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.
Phase 2: Geometric Mean Neutralizing Antibody Titer Ratio, With Respect to Day 1Day 22, Day 43The microneutralization (MN) assay is an alternative assay for determining immunologic response to vaccination. It is a highly sensitive assay that can provide information on the ability of induced antibody to neutralize influenza virus. Titers of neutralizing antibodies were expressed as the amount of the greatest dilution of serum giving a neutralization of 50% of tissue cytopathic effects of the virus in the tissue culture.
Phase 3: Geometric Mean Neutralizing Antibody Titer Ratio, With Respect to Day 1Day 43The MN assay is an alternative assay for determining immunologic response to vaccination. It is a highly sensitive assay that can provide information on the ability of induced antibody to neutralize influenza virus. Titers of neutralizing antibodies were expressed as the amount of the greatest dilution of serum giving a neutralization of 50% of tissue cytopathic effects of the virus in the tissue culture. In Phase 3, MN assay was conducted in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in order to have at least 200 evaluable subjects receiving IVACFLU A/H5N1 and 40 evaluable subjects receiving placebo.
Number and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)21 days after each vaccinationUnsolicited AEs were any AEs that occurred any time after study product was given (temporally related to study product), whether or not deemed related to the product, and were not solicited. Unsolicited AEs were either observed by study staff while the subject was at a clinic for a study visit or reported by the subject at any time. Any solicited sign or symptom starting after 7 days post-study product injection was recorded as an unsolicited AE. For the Phase 2 study, laboratory results were considered AEs when the result was Grade 2 or above. Any medical condition that was present at the time that the subject was enrolled was not reported as an AE, but was reported as a pre-existing condition on the Medical History Form. However, if this condition occurred with greater frequency or severity during the study, it was recorded as an AE.

Countries

Vietnam

Participant flow

Recruitment details

Phase 2 & 3: Recruitment occurred from communes affiliated with the District Health Centers. Commune health workers identified potential participants through home visits and invited interested people to attend an information session. People heard about the study and those interested had individual consent for screening.

Participants by arm

ArmCount
Phase 2: Placebo
Subjects participating in Phase 2 and assigned to receiving two injections of placebo administered intramuscularly as a single dose, separated by 21 days.
100
Phase 2: Vaccine (15 mcg)
Subjects participating in Phase 2 and assigned to receiving two injections of IVACFLU-A/H5N1 vaccine (15 mcg concentration) administered intramuscularly as a single dose, separated by 21 days.
100
Phase 2: Vaccine (30 mcg)
Subjects participating in Phase 2 and assigned to receiving two injections of IVACFLU-A/H5N1 vaccine (30 mcg concentration) administered intramuscularly as a single dose, separated by 21 days.
100
Phase 3: Placebo
Subjects participating in Phase 3 and assigned to receiving two injections of placebo administered intramuscularly as a single dose, separated by 21 days.
105
Phase 3: Vaccine
Subjects participating in Phase 2 and assigned to receiving two injections of IVACFLU-A/H5N1 vaccine (15 mcg concentration) administered intramuscularly as a single dose, separated by 21 days.
525
Total930

Withdrawals & dropouts

PeriodReasonFG000FG001FG002FG003FG004
Phase 2Pregnancy00100
Phase 2Withdrawal by Subject25000
Phase 3Withdrawal by Subject00010

Baseline characteristics

CharacteristicPhase 2: PlaceboPhase 2: Vaccine (15 mcg)Phase 2: Vaccine (30 mcg)Phase 3: PlaceboPhase 3: VaccineTotal
Age, Continuous39.6 years
STANDARD_DEVIATION 9.62
39.8 years
STANDARD_DEVIATION 9.99
39.7 years
STANDARD_DEVIATION 9.63
39.9 years
STANDARD_DEVIATION 9.61
40.2 years
STANDARD_DEVIATION 9.72
40.0 years
STANDARD_DEVIATION 9.7
Race/Ethnicity, Customized
Kinh
100 Participants100 Participants100 Participants105 Participants524 Participants929 Participants
Race/Ethnicity, Customized
Other
0 Participants0 Participants0 Participants0 Participants1 Participants1 Participants
Sex: Female, Male
Female
61 Participants72 Participants65 Participants66 Participants286 Participants550 Participants
Sex: Female, Male
Male
39 Participants28 Participants35 Participants39 Participants239 Participants380 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
EG003
affected / at risk
EG004
affected / at risk
deaths
Total, all-cause mortality
0 / 1000 / 1000 / 1000 / 1050 / 525
other
Total, other adverse events
21 / 10020 / 10024 / 10017 / 10558 / 525
serious
Total, serious adverse events
0 / 1001 / 1000 / 1004 / 1058 / 525

Outcome results

Primary

Number and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40

Serum specimens were tested for the presence of HAI antibodies to influenza. The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.

Time frame: Day 1, Day 43

Population: Subjects who received 2 injections and had valid sera samples for the day measured

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Phase 2: PlaceboNumber and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 10 Participants
Phase 2: PlaceboNumber and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 430 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 10 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 4379 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 10 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 4381 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 430 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 10 Participants
Phase 3: VaccineNumber and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 11 Participants
Phase 3: VaccineNumber and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 4398 Participants
Secondary

Number and Percentage of Subjects Experiencing Reactogenicity

Reported solicited signs and symptoms were recorded by the subject on the Diary Card from Days 1-7 and Days 22-28 in the study, then evaluated by study physician on Days 8, 22, and 29.The evaluated solicited local reactogenicity events were as follows: * Size of redness (at site of injection) in centimeters (cm) * Size of swelling (at site of injection) in cm * Size of induration (hardness at site of injection) in cm * Pain (at site of injection) * Tenderness (at site of injection) The evaluated solicited systemic reactogenicity events were as follows: * Fever/body temperature (and body location of measurement) * Fatigue/malaise * Generalized muscle aches * Joint aches/pains * Chills * Nausea * Vomiting * Headache

Time frame: 7 days after each vaccination

Population: Subjects who received injections

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Phase 2: PlaceboNumber and Percentage of Subjects Experiencing ReactogenicityInjection 1: any local reaction22 Participants
Phase 2: PlaceboNumber and Percentage of Subjects Experiencing ReactogenicityInjection 1: any systemic reaction52 Participants
Phase 2: PlaceboNumber and Percentage of Subjects Experiencing ReactogenicityInjection 2: any local reaction12 Participants
Phase 2: PlaceboNumber and Percentage of Subjects Experiencing ReactogenicityInjection 2: any systemic reaction29 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Experiencing ReactogenicityInjection 1: any local reaction83 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Experiencing ReactogenicityInjection 2: any systemic reaction31 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Experiencing ReactogenicityInjection 1: any systemic reaction66 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Experiencing ReactogenicityInjection 2: any local reaction44 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Experiencing ReactogenicityInjection 2: any systemic reaction37 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Experiencing ReactogenicityInjection 1: any systemic reaction83 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Experiencing ReactogenicityInjection 2: any local reaction50 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Experiencing ReactogenicityInjection 1: any local reaction87 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Experiencing ReactogenicityInjection 1: any local reaction19 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Experiencing ReactogenicityInjection 1: any systemic reaction36 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Experiencing ReactogenicityInjection 2: any systemic reaction19 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Experiencing ReactogenicityInjection 2: any local reaction15 Participants
Phase 3: VaccineNumber and Percentage of Subjects Experiencing ReactogenicityInjection 2: any systemic reaction129 Participants
Phase 3: VaccineNumber and Percentage of Subjects Experiencing ReactogenicityInjection 2: any local reaction227 Participants
Phase 3: VaccineNumber and Percentage of Subjects Experiencing ReactogenicityInjection 1: any systemic reaction286 Participants
Phase 3: VaccineNumber and Percentage of Subjects Experiencing ReactogenicityInjection 1: any local reaction409 Participants
Secondary

Number and Percentage of Subjects Experiencing Reactogenicity

Immediate reactogenicity (30 minutes post-injection) were evaluated on Day 1 and Day 22 and consisted of: * Inspection of the upper arms for the presence or absence of redness, swelling, hardness, pain, or tenderness; and * Documentation of the presence or absence of headache, fever, fatigue/malaise, muscle aches, joint aches, nausea, vomiting, or chills. Immediate reactogenicity were assessed by a study physician or appropriately trained medical staff.

Time frame: 30 minutes after each injection

Population: Subjects who received injections

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Phase 2: PlaceboNumber and Percentage of Subjects Experiencing ReactogenicityInjection 2: any local reaction2 Participants
Phase 2: PlaceboNumber and Percentage of Subjects Experiencing ReactogenicityInjection 1: any local reaction0 Participants
Phase 2: PlaceboNumber and Percentage of Subjects Experiencing ReactogenicityInjection 1: any systemic reaction1 Participants
Phase 2: PlaceboNumber and Percentage of Subjects Experiencing ReactogenicityInjection 2: any systemic reaction0 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Experiencing ReactogenicityInjection 1: any systemic reaction1 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Experiencing ReactogenicityInjection 1: any local reaction1 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Experiencing ReactogenicityInjection 2: any systemic reaction1 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Experiencing ReactogenicityInjection 2: any local reaction2 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Experiencing ReactogenicityInjection 1: any local reaction1 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Experiencing ReactogenicityInjection 2: any systemic reaction0 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Experiencing ReactogenicityInjection 1: any systemic reaction0 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Experiencing ReactogenicityInjection 2: any local reaction2 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Experiencing ReactogenicityInjection 1: any local reaction0 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Experiencing ReactogenicityInjection 2: any systemic reaction2 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Experiencing ReactogenicityInjection 2: any local reaction2 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Experiencing ReactogenicityInjection 1: any systemic reaction0 Participants
Phase 3: VaccineNumber and Percentage of Subjects Experiencing ReactogenicityInjection 2: any systemic reaction2 Participants
Phase 3: VaccineNumber and Percentage of Subjects Experiencing ReactogenicityInjection 1: any local reaction1 Participants
Phase 3: VaccineNumber and Percentage of Subjects Experiencing ReactogenicityInjection 1: any systemic reaction0 Participants
Phase 3: VaccineNumber and Percentage of Subjects Experiencing ReactogenicityInjection 2: any local reaction3 Participants
Secondary

Number and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)

Unsolicited AEs were any AEs that occurred any time after study product was given (temporally related to study product), whether or not deemed related to the product, and were not solicited. Unsolicited AEs were either observed by study staff while the subject was at a clinic for a study visit or reported by the subject at any time. Any solicited sign or symptom starting after 7 days post-study product injection was recorded as an unsolicited AE. For the Phase 2 study, laboratory results were considered AEs when the result was Grade 2 or above. Any medical condition that was present at the time that the subject was enrolled was not reported as an AE, but was reported as a pre-existing condition on the Medical History Form. However, if this condition occurred with greater frequency or severity during the study, it was recorded as an AE.

Time frame: 21 days after each vaccination

Population: Subjects who received injections

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Phase 2: PlaceboNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 1: at least one AE21 Participants
Phase 2: PlaceboNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 1: at least 1 severe AE3 Participants
Phase 2: PlaceboNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 1: at least 1 treatment-related AE1 Participants
Phase 2: PlaceboNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 2: at least one AE6 Participants
Phase 2: PlaceboNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 2: at least 1 severe AE1 Participants
Phase 2: PlaceboNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 2: at least 1 treatment-related AE0 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 2: at least 1 severe AE2 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 2: at least 1 treatment-related AE0 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 1: at least one AE20 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 1: at least 1 treatment-related AE0 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 2: at least one AE10 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 1: at least 1 severe AE0 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 2: at least one AE11 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 2: at least 1 severe AE1 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 1: at least one AE24 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 1: at least 1 treatment-related AE1 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 1: at least 1 severe AE0 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 2: at least 1 treatment-related AE0 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 2: at least one AE16 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 1: at least 1 severe AE0 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 1: at least 1 treatment-related AE0 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 2: at least 1 treatment-related AE0 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 2: at least 1 severe AE1 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 1: at least one AE16 Participants
Phase 3: VaccineNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 2: at least 1 severe AE0 Participants
Phase 3: VaccineNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 1: at least 1 treatment-related AE0 Participants
Phase 3: VaccineNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 1: at least 1 severe AE0 Participants
Phase 3: VaccineNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 2: at least 1 treatment-related AE0 Participants
Phase 3: VaccineNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 2: at least one AE56 Participants
Phase 3: VaccineNumber and Percentage of Subjects Experiencing Unsolicited Adverse Events (AE)Injection 1: at least one AE73 Participants
Secondary

Number and Percentage of Subjects Experiencing Unsolicited Serious Adverse Events (SAE)

Defined as an adverse event that led to death, was life-threatening (subject at immediate risk of death); required inpatient hospitalization or prolongation of existing hospitalization; resulted in congenital anomaly/birth defect; resulted in a persistent or significant disability or incapacity.

Time frame: 90 days

Population: Subjects who received injections

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Phase 2: PlaceboNumber and Percentage of Subjects Experiencing Unsolicited Serious Adverse Events (SAE)0 Participants
Phase 2: Vaccine (15 mcg)Number and Percentage of Subjects Experiencing Unsolicited Serious Adverse Events (SAE)1 Participants
Phase 2: Vaccine (30 mcg)Number and Percentage of Subjects Experiencing Unsolicited Serious Adverse Events (SAE)0 Participants
Phase 3: PlaceboNumber and Percentage of Subjects Experiencing Unsolicited Serious Adverse Events (SAE)4 Participants
Phase 3: VaccineNumber and Percentage of Subjects Experiencing Unsolicited Serious Adverse Events (SAE)8 Participants
Secondary

Phase 2: Geometric Mean Hemagglutination Inhibition (HAI) Titer

Serum specimens were tested for the presence of HAI antibodies to influenza on day 1, day 22, and day 43 (day 1 and 22 prior to injection). The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.

Time frame: Day 1, Day 22, Day 43

Population: Subjects who received the prior injections (as applicable) and had valid sera samples for the day measured

ArmMeasureGroupValue (GEOMETRIC_MEAN)
Phase 2: PlaceboPhase 2: Geometric Mean Hemagglutination Inhibition (HAI) TiterDay 225.52 titer
Phase 2: PlaceboPhase 2: Geometric Mean Hemagglutination Inhibition (HAI) TiterDay 15.48 titer
Phase 2: PlaceboPhase 2: Geometric Mean Hemagglutination Inhibition (HAI) TiterDay 435.63 titer
Phase 2: Vaccine (15 mcg)Phase 2: Geometric Mean Hemagglutination Inhibition (HAI) TiterDay 2231.67 titer
Phase 2: Vaccine (15 mcg)Phase 2: Geometric Mean Hemagglutination Inhibition (HAI) TiterDay 15.62 titer
Phase 2: Vaccine (15 mcg)Phase 2: Geometric Mean Hemagglutination Inhibition (HAI) TiterDay 4362.65 titer
Phase 2: Vaccine (30 mcg)Phase 2: Geometric Mean Hemagglutination Inhibition (HAI) TiterDay 15.68 titer
Phase 2: Vaccine (30 mcg)Phase 2: Geometric Mean Hemagglutination Inhibition (HAI) TiterDay 4359.20 titer
Phase 2: Vaccine (30 mcg)Phase 2: Geometric Mean Hemagglutination Inhibition (HAI) TiterDay 2242.16 titer
Secondary

Phase 2: Geometric Mean Hemagglutination Inhibition (HAI) Titer Ratio, With Respect to Day 1

Serum specimens were tested for the presence of HAI antibodies to influenza on day 1, day 22, and day 43 (day 1 and 22 prior to injection). The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.

Time frame: Day 22, Day 43

Population: Subjects who received the prior injections (as applicable) and had valid sera samples for the day measured

ArmMeasureGroupValue (GEOMETRIC_MEAN)
Phase 2: PlaceboPhase 2: Geometric Mean Hemagglutination Inhibition (HAI) Titer Ratio, With Respect to Day 1Day 221.01 fold change
Phase 2: PlaceboPhase 2: Geometric Mean Hemagglutination Inhibition (HAI) Titer Ratio, With Respect to Day 1Day 431.03 fold change
Phase 2: Vaccine (15 mcg)Phase 2: Geometric Mean Hemagglutination Inhibition (HAI) Titer Ratio, With Respect to Day 1Day 225.64 fold change
Phase 2: Vaccine (15 mcg)Phase 2: Geometric Mean Hemagglutination Inhibition (HAI) Titer Ratio, With Respect to Day 1Day 4311.15 fold change
Phase 2: Vaccine (30 mcg)Phase 2: Geometric Mean Hemagglutination Inhibition (HAI) Titer Ratio, With Respect to Day 1Day 227.42 fold change
Phase 2: Vaccine (30 mcg)Phase 2: Geometric Mean Hemagglutination Inhibition (HAI) Titer Ratio, With Respect to Day 1Day 4310.41 fold change
Secondary

Phase 2: Geometric Mean Neutralizing Antibody Titer

The microneutralization (MN) assay is an alternative assay for determining immunologic response to vaccination. It is a highly sensitive assay that can provide information on the ability of induced antibody to neutralize influenza virus. Titers of neutralizing antibodies were expressed as the amount of the greatest dilution of serum giving a neutralization of 50% of tissue cytopathic effects of the virus in the tissue culture.

Time frame: Day 1, Day 22, Day 43

Population: Subjects who received the prior injections (as applicable) and had valid sera samples for the day measured

ArmMeasureGroupValue (GEOMETRIC_MEAN)
Phase 2: PlaceboPhase 2: Geometric Mean Neutralizing Antibody TiterDay 227.12 titer
Phase 2: PlaceboPhase 2: Geometric Mean Neutralizing Antibody TiterDay 17.15 titer
Phase 2: PlaceboPhase 2: Geometric Mean Neutralizing Antibody TiterDay 437.12 titer
Phase 2: Vaccine (15 mcg)Phase 2: Geometric Mean Neutralizing Antibody TiterDay 2213.78 titer
Phase 2: Vaccine (15 mcg)Phase 2: Geometric Mean Neutralizing Antibody TiterDay 17.10 titer
Phase 2: Vaccine (15 mcg)Phase 2: Geometric Mean Neutralizing Antibody TiterDay 4329.76 titer
Phase 2: Vaccine (30 mcg)Phase 2: Geometric Mean Neutralizing Antibody TiterDay 17.19 titer
Phase 2: Vaccine (30 mcg)Phase 2: Geometric Mean Neutralizing Antibody TiterDay 4328.48 titer
Phase 2: Vaccine (30 mcg)Phase 2: Geometric Mean Neutralizing Antibody TiterDay 2229.76 titer
Secondary

Phase 2: Geometric Mean Neutralizing Antibody Titer Ratio, With Respect to Day 1

The microneutralization (MN) assay is an alternative assay for determining immunologic response to vaccination. It is a highly sensitive assay that can provide information on the ability of induced antibody to neutralize influenza virus. Titers of neutralizing antibodies were expressed as the amount of the greatest dilution of serum giving a neutralization of 50% of tissue cytopathic effects of the virus in the tissue culture.

Time frame: Day 22, Day 43

Population: Subjects who received the prior injections (as applicable) and had valid sera samples for the day measured

ArmMeasureGroupValue (GEOMETRIC_MEAN)
Phase 2: PlaceboPhase 2: Geometric Mean Neutralizing Antibody Titer Ratio, With Respect to Day 1Day 221.00 fold change
Phase 2: PlaceboPhase 2: Geometric Mean Neutralizing Antibody Titer Ratio, With Respect to Day 1Day 431.00 fold change
Phase 2: Vaccine (15 mcg)Phase 2: Geometric Mean Neutralizing Antibody Titer Ratio, With Respect to Day 1Day 221.94 fold change
Phase 2: Vaccine (15 mcg)Phase 2: Geometric Mean Neutralizing Antibody Titer Ratio, With Respect to Day 1Day 434.19 fold change
Phase 2: Vaccine (30 mcg)Phase 2: Geometric Mean Neutralizing Antibody Titer Ratio, With Respect to Day 1Day 222.02 fold change
Phase 2: Vaccine (30 mcg)Phase 2: Geometric Mean Neutralizing Antibody Titer Ratio, With Respect to Day 1Day 433.96 fold change
Secondary

Phase 2: Number and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40

Serum specimens were tested for the presence of HAI antibodies to influenza. The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.

Time frame: Day 1, Day 22

Population: Subjects who received 2 injections and had valid sera samples for the day measured

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Phase 2: PlaceboPhase 2: Number and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 10 Participants
Phase 2: PlaceboPhase 2: Number and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 220 Participants
Phase 2: Vaccine (15 mcg)Phase 2: Number and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 10 Participants
Phase 2: Vaccine (15 mcg)Phase 2: Number and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 2242 Participants
Phase 2: Vaccine (30 mcg)Phase 2: Number and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 10 Participants
Phase 2: Vaccine (30 mcg)Phase 2: Number and Percentage of Subjects Achieving a Hemagglutination Inhibition (HAI) Titer of ≥1:40Day 2256 Participants
Secondary

Phase 2: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Hemagglutination Inhibition (HAI) Titer

Serum specimens were tested for the presence of HAI antibodies to influenza on day 1, day 22, and day 43 (day 1 and 22 prior to injection). The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.

Time frame: Day 22, Day 43

Population: Subjects who received the prior injections (as applicable) and had valid sera samples for the day measured

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Phase 2: PlaceboPhase 2: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Hemagglutination Inhibition (HAI) TiterDay 220 Participants
Phase 2: PlaceboPhase 2: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Hemagglutination Inhibition (HAI) TiterDay 430 Participants
Phase 2: Vaccine (15 mcg)Phase 2: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Hemagglutination Inhibition (HAI) TiterDay 2257 Participants
Phase 2: Vaccine (15 mcg)Phase 2: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Hemagglutination Inhibition (HAI) TiterDay 4388 Participants
Phase 2: Vaccine (30 mcg)Phase 2: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Hemagglutination Inhibition (HAI) TiterDay 2270 Participants
Phase 2: Vaccine (30 mcg)Phase 2: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Hemagglutination Inhibition (HAI) TiterDay 4393 Participants
Secondary

Phase 2: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Neutralizing Antibody Titer

The microneutralization (MN) assay is an alternative assay for determining immunologic response to vaccination. It is a highly sensitive assay that can provide information on the ability of induced antibody to neutralize influenza virus. Titers of neutralizing antibodies were expressed as the amount of the greatest dilution of serum giving a neutralization of 50% of tissue cytopathic effects of the virus in the tissue culture.

Time frame: Day 22, Day 43

Population: Subjects who received the prior injections (as applicable) and had valid sera samples for the day measured

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Phase 2: PlaceboPhase 2: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Neutralizing Antibody TiterDay 220 Participants
Phase 2: PlaceboPhase 2: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Neutralizing Antibody TiterDay 430 Participants
Phase 2: Vaccine (15 mcg)Phase 2: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Neutralizing Antibody TiterDay 2221 Participants
Phase 2: Vaccine (15 mcg)Phase 2: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Neutralizing Antibody TiterDay 4357 Participants
Phase 2: Vaccine (30 mcg)Phase 2: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Neutralizing Antibody TiterDay 2226 Participants
Phase 2: Vaccine (30 mcg)Phase 2: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Neutralizing Antibody TiterDay 4363 Participants
Secondary

Phase 3: Geometric Mean Hemagglutination Inhibition (HAI) Titer

Serum specimens were tested for the presence of HAI antibodies to influenza. The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.

Time frame: Day 1, Day 43

Population: Subjects who received 2 injections and had valid sera samples for the day measured

ArmMeasureGroupValue (GEOMETRIC_MEAN)
Phase 2: PlaceboPhase 3: Geometric Mean Hemagglutination Inhibition (HAI) TiterDay 15.04 titer
Phase 2: PlaceboPhase 3: Geometric Mean Hemagglutination Inhibition (HAI) TiterDay 435.20 titer
Phase 2: Vaccine (15 mcg)Phase 3: Geometric Mean Hemagglutination Inhibition (HAI) TiterDay 15.08 titer
Phase 2: Vaccine (15 mcg)Phase 3: Geometric Mean Hemagglutination Inhibition (HAI) TiterDay 4327.61 titer
Secondary

Phase 3: Geometric Mean Hemagglutination Inhibition (HAI) Titer Ratio, With Respect to Day 1

Serum specimens were tested for the presence of HAI antibodies to influenza. The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.

Time frame: Day 43

Population: Subjects who received 2 injections and had valid sera samples for the day measured

ArmMeasureValue (GEOMETRIC_MEAN)
Phase 2: PlaceboPhase 3: Geometric Mean Hemagglutination Inhibition (HAI) Titer Ratio, With Respect to Day 11.01 fold change
Phase 2: Vaccine (15 mcg)Phase 3: Geometric Mean Hemagglutination Inhibition (HAI) Titer Ratio, With Respect to Day 15.31 fold change
Secondary

Phase 3: Geometric Mean Neutralizing Antibody Titer

Serum specimens were tested for the presence of HAI antibodies to influenza. The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.

Time frame: Day 1, Day 43

Population: Subjects who received 2 injections and had valid sera samples for the day measured

ArmMeasureGroupValue (GEOMETRIC_MEAN)
Phase 2: PlaceboPhase 3: Geometric Mean Neutralizing Antibody TiterDay 17.07 titer
Phase 2: PlaceboPhase 3: Geometric Mean Neutralizing Antibody TiterDay 437.07 titer
Phase 2: Vaccine (15 mcg)Phase 3: Geometric Mean Neutralizing Antibody TiterDay 17.07 titer
Phase 2: Vaccine (15 mcg)Phase 3: Geometric Mean Neutralizing Antibody TiterDay 4326.16 titer
Secondary

Phase 3: Geometric Mean Neutralizing Antibody Titer Ratio, With Respect to Day 1

The MN assay is an alternative assay for determining immunologic response to vaccination. It is a highly sensitive assay that can provide information on the ability of induced antibody to neutralize influenza virus. Titers of neutralizing antibodies were expressed as the amount of the greatest dilution of serum giving a neutralization of 50% of tissue cytopathic effects of the virus in the tissue culture. In Phase 3, MN assay was conducted in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in order to have at least 200 evaluable subjects receiving IVACFLU A/H5N1 and 40 evaluable subjects receiving placebo.

Time frame: Day 43

Population: Subjects who received 2 injections and had valid sera samples for the day measured

ArmMeasureValue (GEOMETRIC_MEAN)
Phase 2: PlaceboPhase 3: Geometric Mean Neutralizing Antibody Titer Ratio, With Respect to Day 11.00 fold change
Phase 2: Vaccine (15 mcg)Phase 3: Geometric Mean Neutralizing Antibody Titer Ratio, With Respect to Day 13.70 fold change
Secondary

Phase 3: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Hemagglutination Inhibition (HAI) Titer

Serum specimens were tested for the presence of HAI antibodies to influenza. The HAI assay was conducted using serum samples from all the subjects in Phase 2 of the study and in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in Phase 3 in order to have at least 200 evaluable subjects receiving IVACFLU-A/H5N1 and 40 evaluable subjects receiving placebo, at the end of study.

Time frame: Day 43

Population: Subjects who received 2 injections and had valid sera samples for the day measured

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Phase 2: PlaceboPhase 3: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Hemagglutination Inhibition (HAI) Titer0 Participants
Phase 2: Vaccine (15 mcg)Phase 3: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Hemagglutination Inhibition (HAI) Titer150 Participants
Secondary

Phase 3: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Neutralizing Antibody Titer

The MN assay is an alternative assay for determining immunologic response to vaccination. It is a highly sensitive assay that can provide information on the ability of induced antibody to neutralize influenza virus. Titers of neutralizing antibodies were expressed as the amount of the greatest dilution of serum giving a neutralization of 50% of tissue cytopathic effects of the virus in the tissue culture. In Phase 3, MN assay was conducted in a subset of approximately 270 subjects receiving the IVACFLU-A/H5N1 vaccine (vaccinees) and placebo from one study site in order to have at least 200 evaluable subjects receiving IVACFLU A/H5N1 and 40 evaluable subjects receiving placebo.

Time frame: Day 43

Population: Subjects who received 2 injections and had valid sera samples for the day measured

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Phase 2: PlaceboPhase 3: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Neutralizing Antibody Titer0 Participants
Phase 2: Vaccine (15 mcg)Phase 3: Number and Percentage of Subjects Achieving at Least a 4-fold Increase in Neutralizing Antibody Titer114 Participants

Source: ClinicalTrials.gov · Data processed: Feb 20, 2026