Trial Outcomes & Findings for Efficacy, Safety, and Immunogenicity of a Plant-Derived Quadrivalent Virus-Like Particles (VLPs) Influenza Vaccine in Adults (NCT NCT03301051)

Last Updated: 2023-08-14

Results Overview

Occurrences of protocol-defined respiratory illness caused by vaccine-matched influenza strains were assessed. The vaccine-matched strains included: H1N1 (A/Michigan/45/2015); H3N2 (A/Hong Kong/4801/2014); B/Brisbane (B/Brisbane/60/2008); and B/Phuket (B/Phuket/3073/2013A). The protocol-defined respiratory illness was determined by the occurrence of at least 1 of the following respiratory symptoms: sneezing, stuffy nose, sore throat, cough, sputum production, wheezing, or difficulty breathing. Occurrences of all matched strains are reported.

Recruitment status

COMPLETED

Study phase

PHASE3

Target enrollment

10160 participants

Primary outcome timeframe

Day 14 (post-vaccination) up to ~8 months

Results posted on

2023-08-14

Participant Flow

Participants were randomized in a 1:1 ratio to receive the Quadrivalent virus-like particle (VLP) Influenza Vaccine at a dose of 30 μg/strain or the placebo.

Participants were healthy adults 18 to 64 years of age assessed during the 2017-2018 influenza season.

Participant milestones

Participant milestones
Measure	Quadrivalent VLP Vaccine Participants received one intramuscular (IM) injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo Participants received one IM injection of 0.5 mL of placebo on Day 0.
Overall Study STARTED	5077	5083
Overall Study Safety Analysis Set	5064	5072
Overall Study Vaccinated	5065	5072
Overall Study COMPLETED	4731	4711
Overall Study NOT COMPLETED	346	372

Reasons for withdrawal

Reasons for withdrawal
Measure	Quadrivalent VLP Vaccine Participants received one intramuscular (IM) injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo Participants received one IM injection of 0.5 mL of placebo on Day 0.
Overall Study Adverse Event	0	4
Overall Study Withdrawal by Subject	59	65
Overall Study Lost to Follow-up	263	282
Overall Study Protocol Violation	1	3
Overall Study Physician Decision	1	3
Overall Study Death	1	1
Overall Study Miscellaneous	8	4
Overall Study Randomized, not vaccinated	13	10

Baseline Characteristics

Efficacy, Safety, and Immunogenicity of a Plant-Derived Quadrivalent Virus-Like Particles (VLPs) Influenza Vaccine in Adults

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Quadrivalent VLP Vaccine n=5064 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=5072 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.	Total n=10136 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	5064 Participants n=5 Participants	5072 Participants n=7 Participants	10136 Participants n=5 Participants
Age, Categorical >=65 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Sex: Female, Male Female	3051 Participants n=5 Participants	3034 Participants n=7 Participants	6085 Participants n=5 Participants
Sex: Female, Male Male	2013 Participants n=5 Participants	2038 Participants n=7 Participants	4051 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	293 Participants n=5 Participants	326 Participants n=7 Participants	619 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	4769 Participants n=5 Participants	4740 Participants n=7 Participants	9509 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	2 Participants n=5 Participants	6 Participants n=7 Participants	8 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	20 Participants n=5 Participants	18 Participants n=7 Participants	38 Participants n=5 Participants
Race (NIH/OMB) Asian	1192 Participants n=5 Participants	1185 Participants n=7 Participants	2377 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	7 Participants n=5 Participants	6 Participants n=7 Participants	13 Participants n=5 Participants
Race (NIH/OMB) Black or African American	646 Participants n=5 Participants	620 Participants n=7 Participants	1266 Participants n=5 Participants
Race (NIH/OMB) White	3168 Participants n=5 Participants	3214 Participants n=7 Participants	6382 Participants n=5 Participants
Race (NIH/OMB) More than one race	23 Participants n=5 Participants	23 Participants n=7 Participants	46 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	8 Participants n=5 Participants	6 Participants n=7 Participants	14 Participants n=5 Participants

PRIMARY outcome

Timeframe: Day 14 (post-vaccination) up to ~8 months

Population: The Per Protocol (PP) set consisted of the participants who participated in the study until at least the end of the peak period or for at least five months or until the end of the surveillance period.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=4814 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=4812 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Number of Occurrences of Protocol-Defined Respiratory Illness Caused by Vaccine-Matched Influenza Strains	110 Number of cases	169 Number of cases

SECONDARY outcome

Timeframe: Day 14 (post-vaccination) up to ~8 months

Population: PP Set

Occurrences of protocol-defined respiratory illness due to laboratory-confirmed influenza strain (matched, mismatched, and un-typed) were assessed. A protocol-defined respiratory illness was determined by the occurrence of at least 1 of the following respiratory symptoms: sneezing, stuffy nose, sore throat, cough, sputum production, wheezing, or difficulty breathing.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=4814 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=4812 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Number of Occurrences of Protocol-Defined Respiratory Illness Cases Caused by Any Laboratory Confirmed Influenza Strain	213 Number of cases	347 Number of cases

SECONDARY outcome

Timeframe: Day 14 (post-vaccination) up to ~8 months

Population: PP Set

Occurrences of protocol-defined ILI due to laboratory-confirmed influenza caused by influenza viral types/subtypes that are matched (and/or antigenically similar) to the strains covered in the vaccine formulation were assessed. A participant is considered to have protocol-defined ILI if the participant met at least one of the following pre-defined respiratory symptoms: sore throat, cough, sputum production, wheezing, or difficulty breathing AND at least one of the following systemic symptoms: fever (defined as a temperature \> 37.2 °C or \> 99.0 °F), chills, tiredness, headache or myalgia.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=4814 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=4812 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Number of Occurrences of Laboratory-Confirmed Protocol-Defined Influenza-Like Illness (ILI) Caused by Vaccine-Matched Influenza Strains	98 Number of cases	148 Number of cases

SECONDARY outcome

Timeframe: Day 14 (post-vaccination) up to ~8 months

Population: PP Set

Occurrences of laboratory-confirmed ILI caused by any influenza viral strains were assessed. A participant is considered to have protocol-defined ILI if the participant met at least one of the following pre-defined respiratory symptoms: sore throat, cough, sputum production, wheezing, or difficulty breathing AND at least one of the following systemic symptoms: fever (defined as a temperature \> 37.2 °C or \> 99.0 °F), chills, tiredness, headache or myalgia.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=4814 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=4812 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Number of Occurrences of Laboratory-Confirmed ILI Caused by Any Influenza Strain	178 Number of cases	285 Number of cases

SECONDARY outcome

Timeframe: Day 14 (post-vaccination) up to ~8 months

Population: PP Set

Occurrences of protocol-defined ILI cases (confirmed or not) were assessed. A participant is considered to have protocol-defined ILI if the participant met at least one of the following pre-defined respiratory symptoms: sore throat, cough, sputum production, wheezing, or difficulty breathing AND at least one of the following systemic symptoms: fever (defined as a temperature \> 37.2 °C or \> 99.0 °F), chills, tiredness, headache or myalgia.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=4814 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=4812 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Number of Occurrences of Protocol-Defined ILI Cases	1576 Number of cases	1679 Number of cases

SECONDARY outcome

Timeframe: 15 minutes post vaccination

Population: SAS

Immediate complaints were defined as any solicited local or systemic reactions. Solicited local reactions included: erythema, swelling, and pain at the injection site and solicited systemic reactions included: fever, headache, fatigue, muscle aches, joint aches, chills, a feeling of general discomfort, swelling in the axilla, and swelling in the neck.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=5064 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=5072 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Number of Participants With at Least One Immediate Complaint	441 Participants	377 Participants

SECONDARY outcome

Timeframe: Day 0 (post-vaccination) up to Day 7

Population: SAS

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=5064 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=5072 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Number of Participants With at Least One Solicited Local and Systemic Reactions	2776 Participants	1723 Participants

SECONDARY outcome

Timeframe: Day 0 (post-vaccination) up to Day 7

Population: SAS

Participants were monitored for both solicited local reactions (erythema, swelling, and pain at the injection site) and solicited systemic reactions (fever, headache, fatigue, muscle aches, joint aches, chills, a feeling of general discomfort, swelling in the axilla, and swelling in the neck). Any solicited local or systemic immediate complaint was also included. The intensity of the solicited reactions was graded as mild (1)-easily tolerated and does not interfere with usual activity; moderate (2)-interferes with daily activity, but the participant is still able to function; severe (3)-incapacitating and the participant is unable to work or complete usual activity or potentially life threatening; (4)-likely to be life-threatening if not treated in a timely manner, according to the Food and Drug Administration (FDA) Guidance for Industry: Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=5064 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=5072 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Number of Participants With ≥ Severe Solicited Local and Systemic Reactions	75 Participants	85 Participants

SECONDARY outcome

Timeframe: Day 0 (post-vaccination) up to Day 7

Population: SAS

Participants were monitored for both solicited local reactions (erythema, swelling, and pain at the injection site) and solicited systemic reactions (fever, headache, fatigue, muscle aches, joint aches, chills, a feeling of general discomfort, swelling in the axilla, and swelling in the neck). The intensity of the solicited reactions was graded according to the FDA Toxicity Grading Scale: mild (1), moderate (2), severe (3) or potentially life threatening (4). The causal relationship with the study vaccine was assessed as "definitely not related" (clearly not related), "probably not related" (no medical evidence), "possibly related" (reasonable possibility of cause and effect), "probably related" (plausible biologic mechanism and temporal relationship) or "definitely related" (direct cause and effect relationship). The ≥ severe events included "severe" and "potentially life-threatening" and the related category included "possibly related", "probably related", and "definitely related."

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=5064 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=5072 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Number of Participants With ≥ Severe Related Solicited Reactions	56 Participants	62 Participants

SECONDARY outcome

Timeframe: Day 0 (post-vaccination) up to Day 21

Population: SAS

Participants were monitored for unsolicited TEAEs (e.g., nasopharyngitis, upper respiratory tract infection, headache, and oropharyngeal pain). An adverse event (AE) or adverse experience was defined as any untoward medical occurrence in a participant or clinical investigation participant who was administered a pharmaceutical product, with or without a causal relationship with the treatment. An AE can be any favorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product, whether or not related to a medicinal product. An AE was considered treatment-emergent if it began on or after the date and time of Study Day 0 vaccination.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=5064 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=5072 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Number of Participants With Unsolicited Treatment-Emergent Adverse Events (TEAEs)	661 Participants	639 Participants

SECONDARY outcome

Timeframe: Day 0 (post-vaccination) up to Day 21

Population: SAS

The intensity of the unsolicited TEAEs was graded as mild (1)-easily tolerated and does not interfere with usual activity; moderate (2)-interferes with daily activity, but the participant is still able to function; severe (3)-incapacitating and the participant is unable to work or complete usual activity or potentially life threatening; (4)-likely to be life-threatening if not treated in a timely manner, according to the FDA Guidance for Industry: Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials. The ≥ Severe events included severe and potentially life-threatening events. AE and TEAEs are defined in outcome measure #10.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=5064 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=5072 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Number of Participants With ≥ Severe Unsolicited TEAEs	13 Participants	25 Participants

SECONDARY outcome

Timeframe: Day 0 (post-vaccination) up to Day 21

Population: SAS

The intensity of the solicited local and systemic reactions was graded as: mild (1), moderate (2), severe (3) or potentially life threatening (4). The causal relationship with the study vaccine was assessed as "definitely not related" (clearly not related), "probably not related" (no medical evidence), "possibly related" (reasonable possibility of cause and effect), "probably related" (plausible biologic mechanism and temporal relationship) or "definitely related" (direct cause and effect relationship). The ≥ severe events included "severe" and "potentially life-threatening" and the related category included "possibly related", "probably related", and "definitely related." AE and TEAEs are defined in outcome measure #10.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=5064 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=5072 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Number of Participants With ≥ Severe Related Unsolicited Reactions	4 Participants	6 Participants

SECONDARY outcome

Timeframe: Day 0 up to ~8 months

Population: SAS

The number of participants in each treatment group with an occurrence of death was assessed.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=5064 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=5072 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Number of Participants With an Occurrence of Death	1 Participants	2 Participants

SECONDARY outcome

Timeframe: Day 0 up to ~8 months

Population: SAS

A serious adverse event (SAE) is an AE that results in death, is life threatening, results in a persistent or significant disability or incapacity, results in or prolongs an existing hospitalization, is a congenital anomaly or birth defect, or is another important medical event. An SAE was considered treatment-emergent if it was aggravated in severity or frequency following the administration of the study vaccine, up to and including the last visit of the study. AE is defined in outcome measure #10.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=5064 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=5072 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Number of Participants With at Least One Serious TEAE	55 Participants	51 Participants

SECONDARY outcome

Timeframe: Day 0 up to ~8 months

Population: SAS

An AE or adverse experience was defined as any untoward medical occurrence in a participant or clinical investigation participant who was administered a pharmaceutical product, with or without a causal relationship with the treatment. An AE can be any favorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product, whether or not related to a medicinal product. The number of participants with at least one adverse event leading to withdrawal was assessed.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=5064 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=5072 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Number of Participants With at Least One AE Leading to Withdrawal	0 Participants	5 Participants

SECONDARY outcome

Timeframe: Day 0 up to ~8 months

Population: SAS

All NOCDs that may plausibly have an allergic, autoimmune or inflammatory component were assessed and reported. Plausibility should be interpreted broadly; the only clear exceptions are degenerative conditions such as osteoarthritis, age-related physiologic changes and life-style diseases In this context, most cancers, cardiac conditions and kidney diseases should be reported.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=5064 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=5072 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Number of Participants With at Least One New Onset Chronic Diseases (NOCDs)	54 Participants	41 Participants

SECONDARY outcome

Timeframe: Day 0 (pre-vaccination), Day 21

Population: Immunogenicity Per Protocol (IPP) Set consisted of a subset of participants who participated in the immunogenicity portion of the study, who had a Day 21 immunogenicity sample collection.

The GMTs in each treatment group were measured using a HI assay for the homologous strains: H1 A/Michigan/45/2015 (H1N1), A/Hong Kong/4801/2014 (H3N2), B/Brisbane/60/2008, B/Phuket/3073/2013, and the heterologous strains: A/Brisbane/59/2007 (IVR-148) (HIN1), A/Uruguay/716/2007 (H3N2), B/Florida/4/2006, B/Malaysia/2506/2004.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=278 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=97 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Geometric Mean Titers (GMTs) of Hemagglutination Inhibition (HI) Antibody Response for Each Homologous and Heterologous Influenza Strain Heterologous (H3N2): Day 0	17.2 Titers Interval 14.7 to 20.2	19.7 Titers Interval 15.4 to 25.3
Geometric Mean Titers (GMTs) of Hemagglutination Inhibition (HI) Antibody Response for Each Homologous and Heterologous Influenza Strain Homologous (HIN1): Day 0	24.2 Titers Interval 20.7 to 28.3	30.0 Titers Interval 22.9 to 39.3
Geometric Mean Titers (GMTs) of Hemagglutination Inhibition (HI) Antibody Response for Each Homologous and Heterologous Influenza Strain Homologous (HIN1): Day 21	84.8 Titers Interval 71.4 to 100.8	27.8 Titers Interval 21.6 to 35.9
Geometric Mean Titers (GMTs) of Hemagglutination Inhibition (HI) Antibody Response for Each Homologous and Heterologous Influenza Strain Homologous (H3N2): Day 0	26.2 Titers Interval 21.8 to 31.4	29.0 Titers Interval 21.9 to 38.4
Geometric Mean Titers (GMTs) of Hemagglutination Inhibition (HI) Antibody Response for Each Homologous and Heterologous Influenza Strain Homologous (H3N2): Day 21	144.9 Titers Interval 121.9 to 172.4	28.0 Titers Interval 20.9 to 37.4
Geometric Mean Titers (GMTs) of Hemagglutination Inhibition (HI) Antibody Response for Each Homologous and Heterologous Influenza Strain Homologous (B/Brisbane/60/2008): Day 0	12.8 Titers Interval 11.3 to 14.4	12.9 Titers Interval 10.6 to 15.7
Geometric Mean Titers (GMTs) of Hemagglutination Inhibition (HI) Antibody Response for Each Homologous and Heterologous Influenza Strain Homologous (B/Brisbane/60/2008): Day 21	28.1 Titers Interval 24.8 to 31.9	12.1 Titers Interval 10.0 to 14.8
Geometric Mean Titers (GMTs) of Hemagglutination Inhibition (HI) Antibody Response for Each Homologous and Heterologous Influenza Strain Homologous (B/Phuket/3073/2013): Day 0	28.8 Titers Interval 24.5 to 33.9	28.1 Titers Interval 21.7 to 36.5
Geometric Mean Titers (GMTs) of Hemagglutination Inhibition (HI) Antibody Response for Each Homologous and Heterologous Influenza Strain Homologous (B/Phuket/3073/2013): Day 21	87.8 Titers Interval 74.3 to 103.9	26.4 Titers Interval 20.4 to 34.1
Geometric Mean Titers (GMTs) of Hemagglutination Inhibition (HI) Antibody Response for Each Homologous and Heterologous Influenza Strain Heterologous (HIN1): Day 0	14.5 Titers Interval 12.7 to 16.6	14.5 Titers Interval 12.0 to 17.5
Geometric Mean Titers (GMTs) of Hemagglutination Inhibition (HI) Antibody Response for Each Homologous and Heterologous Influenza Strain Heterologous (HIN1): Day 21	16.4 Titers Interval 14.4 to 18.8	14.4 Titers Interval 11.8 to 17.6
Geometric Mean Titers (GMTs) of Hemagglutination Inhibition (HI) Antibody Response for Each Homologous and Heterologous Influenza Strain Heterologous (H3N2): Day 21	44.1 Titers Interval 37.1 to 52.3	17.7 Titers Interval 13.9 to 22.6
Geometric Mean Titers (GMTs) of Hemagglutination Inhibition (HI) Antibody Response for Each Homologous and Heterologous Influenza Strain Heterologous (B/Florida/4/2006): Day 0	26.8 Titers Interval 22.8 to 31.6	31.5 Titers Interval 24.2 to 41.1
Geometric Mean Titers (GMTs) of Hemagglutination Inhibition (HI) Antibody Response for Each Homologous and Heterologous Influenza Strain Heterologous (B/Florida/4/2006): Day 21	65.3 Titers Interval 55.8 to 76.5	26.0 Titers Interval 20.1 to 33.7
Geometric Mean Titers (GMTs) of Hemagglutination Inhibition (HI) Antibody Response for Each Homologous and Heterologous Influenza Strain Heterologous (B/Malaysia/2506/2004): Day 0	11.5 Titers Interval 10.2 to 12.9	10.7 Titers Interval 8.8 to 13.0
Geometric Mean Titers (GMTs) of Hemagglutination Inhibition (HI) Antibody Response for Each Homologous and Heterologous Influenza Strain Heterologous (B/Malaysia/2506/2004): Day 21	24.6 Titers Interval 21.6 to 27.9	10.6 Titers Interval 8.7 to 12.9

SECONDARY outcome

Timeframe: Day 0 (pre-vaccination) up to Day 21

Population: IPP Set

Seroconversion rate: the percentage of participants in a given treatment group with either a ≥ 4-fold increase in reciprocal HI titers between Day 0 and Day 21 or a rise of undetectable HI titer (i.e. \< 10) pre-vaccination (Day 0) to an HI titer of ≥ 40 on Day 21 was measured using an HI assay for the homologous strains: H1 A/Michigan/45/2015 (H1N1), A/Hong Kong/4801/2014 (H3N2), B/Brisbane/60/2008, B/Phuket/3073/2013, and the heterologous strains: A/Brisbane/59/2007 (IVR-148) (HIN1), A/Uruguay/716/2007 (H3N2), B/Florida/4/2006, B/Malaysia/2506/2004.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=278 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=97 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Percentage of Participants With Seroconversion Measured by HI Antibody Response for Each Homologous and Heterologous Strain Heterologous (B/Florida/4/2006)	27.0 Percentage of Participants Interval 21.9 to 32.6	0 Percentage of Participants Interval 0.0 to 0.0
Percentage of Participants With Seroconversion Measured by HI Antibody Response for Each Homologous and Heterologous Strain Heterologous (B/Malaysia/2506/2004)	18.3 Percentage of Participants Interval 14.0 to 23.4	0 Percentage of Participants Interval 0.0 to 0.0
Percentage of Participants With Seroconversion Measured by HI Antibody Response for Each Homologous and Heterologous Strain Homologous (HIN1)	37.1 Percentage of Participants Interval 31.4 to 43.0	0 Percentage of Participants Interval 0.0 to 0.0
Percentage of Participants With Seroconversion Measured by HI Antibody Response for Each Homologous and Heterologous Strain Homologous (H3N2)	46.4 Percentage of Participants Interval 40.4 to 52.5	0 Percentage of Participants Interval 0.0 to 0.0
Percentage of Participants With Seroconversion Measured by HI Antibody Response for Each Homologous and Heterologous Strain Homologous (B/Brisbane/60/2008)	17.6 Percentage of Participants Interval 13.3 to 22.6	0 Percentage of Participants Interval 0.0 to 0.0
Percentage of Participants With Seroconversion Measured by HI Antibody Response for Each Homologous and Heterologous Strain Homologous (B/Phuket/3073/2013)	31.7 Percentage of Participants Interval 26.2 to 37.5	0 Percentage of Participants Interval 0.0 to 0.0
Percentage of Participants With Seroconversion Measured by HI Antibody Response for Each Homologous and Heterologous Strain Heterologous (HIN1)	2.5 Percentage of Participants Interval 1.0 to 5.1	0 Percentage of Participants Interval 0.0 to 0.0
Percentage of Participants With Seroconversion Measured by HI Antibody Response for Each Homologous and Heterologous Strain Heterologous (H3N2)	23.0 Percentage of Participants Interval 18.2 to 28.4	0 Percentage of Participants Interval 0.0 to 0.0

SECONDARY outcome

Timeframe: Day 0 (pre-vaccination) up to Day 21

Population: IPP Set

Seroprotection rate: the percentage of participants in a given treatment group attaining a reciprocal HI titer of ≥ 40 on Day 21 (the percentage of vaccine recipients with a serum HI titer of at least 1:40 following vaccination) was measured using an HI assay for the homologous strains: H1 A/Michigan/45/2015 (H1N1), A/Hong Kong/4801/2014 (H3N2), B/Brisbane/60/2008, B/Phuket/3073/2013, and the heterologous strains: A/Brisbane/59/2007 (IVR-148) (HIN1), A/Uruguay/716/2007 (H3N2), B/Florida/4/2006, B/Malaysia/2506/2004.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=278 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=97 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Percentage of Participants With Seroprotection Measured by HI Antibody Response for Each Homologous and Heterologous Strain Homologous (HIN1): Day 0	40.6 Percentage of Participants Interval 34.8 to 46.7	47.4 Percentage of Participants Interval 37.2 to 57.8
Percentage of Participants With Seroprotection Measured by HI Antibody Response for Each Homologous and Heterologous Strain Homologous (HIN1): Day 21	74.8 Percentage of Participants Interval 69.3 to 79.8	39.2 Percentage of Participants Interval 29.4 to 49.6
Percentage of Participants With Seroprotection Measured by HI Antibody Response for Each Homologous and Heterologous Strain Homologous (H3N2): Day 0	46.4 Percentage of Participants Interval 40.4 to 52.5	46.4 Percentage of Participants Interval 36.2 to 56.8
Percentage of Participants With Seroprotection Measured by HI Antibody Response for Each Homologous and Heterologous Strain Homologous (H3N2): Day 21	85.3 Percentage of Participants Interval 80.5 to 89.2	48.5 Percentage of Participants Interval 38.2 to 58.8
Percentage of Participants With Seroprotection Measured by HI Antibody Response for Each Homologous and Heterologous Strain Homologous (B/Brisbane/60/2008): Day 0	19.4 Percentage of Participants Interval 14.9 to 24.6	20.6 Percentage of Participants Interval 13.1 to 30.0
Percentage of Participants With Seroprotection Measured by HI Antibody Response for Each Homologous and Heterologous Strain Homologous (B/Brisbane/60/2008: Day 21	41.0 Percentage of Participants Interval 35.2 to 47.0	15.5 Percentage of Participants Interval 8.9 to 24.2
Percentage of Participants With Seroprotection Measured by HI Antibody Response for Each Homologous and Heterologous Strain Homologous (B/Phuket/3073/2013): Day 0	47.5 Percentage of Participants Interval 41.5 to 53.5	46.4 Percentage of Participants Interval 36.2 to 56.8
Percentage of Participants With Seroprotection Measured by HI Antibody Response for Each Homologous and Heterologous Strain Homologous (B/Phuket/3073/2013): Day 21	76.3 Percentage of Participants Interval 70.8 to 81.1	43.3 Percentage of Participants Interval 33.3 to 53.7
Percentage of Participants With Seroprotection Measured by HI Antibody Response for Each Homologous and Heterologous Strain Heterologous (HIN1): Day 0	23.4 Percentage of Participants Interval 18.5 to 28.8	16.5 Percentage of Participants Interval 9.7 to 25.4
Percentage of Participants With Seroprotection Measured by HI Antibody Response for Each Homologous and Heterologous Strain Heterologous (HIN1): Day 21	27.0 Percentage of Participants Interval 21.9 to 32.6	16.5 Percentage of Participants Interval 9.7 to 25.4
Percentage of Participants With Seroprotection Measured by HI Antibody Response for Each Homologous and Heterologous Strain Heterologous (H3N2): Day 0	31.3 Percentage of Participants Interval 25.9 to 37.1	34.0 Percentage of Participants Interval 24.7 to 44.3
Percentage of Participants With Seroprotection Measured by HI Antibody Response for Each Homologous and Heterologous Strain Heterologous (H3N2): Day 21	58.6 Percentage of Participants Interval 52.6 to 64.5	29.9 Percentage of Participants Interval 21.0 to 40.0
Percentage of Participants With Seroprotection Measured by HI Antibody Response for Each Homologous and Heterologous Strain Heterologous (B/Florida/4/2006): Day 0	46.8 Percentage of Participants Interval 40.8 to 52.8	48.5 Percentage of Participants Interval 38.2 to 58.8
Percentage of Participants With Seroprotection Measured by HI Antibody Response for Each Homologous and Heterologous Strain Heterologous (B/Florida/4/2006): Day 21	70.9 Percentage of Participants Interval 65.1 to 76.1	46.4 Percentage of Participants Interval 36.2 to 56.8
Percentage of Participants With Seroprotection Measured by HI Antibody Response for Each Homologous and Heterologous Strain Heterologous (B/Malaysia/2506/2004): Day 0	20.1 Percentage of Participants Interval 15.6 to 25.3	15.5 Percentage of Participants Interval 8.9 to 24.2
Percentage of Participants With Seroprotection Measured by HI Antibody Response for Each Homologous and Heterologous Strain Heterologous (B/Malaysia/2506/2004): Day 21	43.2 Percentage of Participants Interval 37.3 to 49.2	13.4 Percentage of Participants Interval 7.3 to 21.8

SECONDARY outcome

Timeframe: Day 0 (pre-vaccination), Day 21

Population: IPP Set

GMFR, the geometric mean of the ratio of GMTs (Day 21/Day 0) in each treatment group was measured using an HI assay for the homologous strains: H1 A/Michigan/45/2015 (H1N1), A/Hong Kong/4801/2014 (H3N2), B/Brisbane/60/2008, B/Phuket/3073/2013, and the heterologous strains: A/Brisbane/59/2007 (IVR-148) (HIN1), A/Uruguay/716/2007 (H3N2), B/Florida/4/2006, B/Malaysia/2506/2004.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=278 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=97 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Geometric Mean Fold Ratio (GMFR) of HI Antibody Response for Each Homologous and Heterologous Strain Homologous (HIN1)	3.4 Ratio Interval 3.0 to 3.9	1.0 Ratio Interval 0.8 to 1.2
Geometric Mean Fold Ratio (GMFR) of HI Antibody Response for Each Homologous and Heterologous Strain Homologous (H3N2)	5.5 Ratio Interval 4.7 to 6.3	1.0 Ratio Interval 0.8 to 1.3
Geometric Mean Fold Ratio (GMFR) of HI Antibody Response for Each Homologous and Heterologous Strain Homologous (B/Brisbane/60/2008)	2.2 Ratio Interval 2.0 to 2.4	0.9 Ratio Interval 0.8 to 1.1
Geometric Mean Fold Ratio (GMFR) of HI Antibody Response for Each Homologous and Heterologous Strain Homologous (B/Phuket/3073/2013)	3.1 Ratio Interval 2.7 to 3.4	0.9 Ratio Interval 0.8 to 1.1
Geometric Mean Fold Ratio (GMFR) of HI Antibody Response for Each Homologous and Heterologous Strain Heterologous (HIN1)	1.1 Ratio Interval 1.1 to 1.2	1.0 Ratio Interval 0.9 to 1.1
Geometric Mean Fold Ratio (GMFR) of HI Antibody Response for Each Homologous and Heterologous Strain Heterologous (H3N2)	2.5 Ratio Interval 2.3 to 2.9	0.9 Ratio Interval 0.8 to 1.1
Geometric Mean Fold Ratio (GMFR) of HI Antibody Response for Each Homologous and Heterologous Strain Heterologous (B/Florida/4/2006)	2.4 Ratio Interval 2.2 to 2.7	0.9 Ratio Interval 0.7 to 1.0
Geometric Mean Fold Ratio (GMFR) of HI Antibody Response for Each Homologous and Heterologous Strain Heterologous (B/Malaysia/2506/2004)	2.2 Ratio Interval 2.0 to 2.4	1.0 Ratio Interval 0.8 to 1.1

SECONDARY outcome

Timeframe: Day 0 (pre-vaccination), Day 21

Population: IPP Set

The GMTs in each treatment group were measured using an MN assay for homologous strains: H1 A/Michigan/45/2015 (H1N1), A/Hong Kong/4801/2014 (H3N2), B/Brisbane/60/2008, B/Phuket/3073/2013.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=278 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=97 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
GMTs of Microneutralization (MN) Antibody Response for Each Homologous Strain Homologous (H3N2): Day 21	120.3 Titers Interval 108.9 to 132.9	67.2 Titers Interval 57.0 to 79.1
GMTs of Microneutralization (MN) Antibody Response for Each Homologous Strain Homologous (HIN1): Day 0	88.1 Titers Interval 76.7 to 101.1	112.3 Titers Interval 91.1 to 138.6
GMTs of Microneutralization (MN) Antibody Response for Each Homologous Strain Homologous (HIN1): Day 21	366.1 Titers Interval 316.1 to 424.1	135.7 Titers Interval 110.4 to 166.9
GMTs of Microneutralization (MN) Antibody Response for Each Homologous Strain Homologous (H3N2): Day 0	46.7 Titers Interval 41.9 to 52.1	62.1 Titers Interval 53.1 to 72.6
GMTs of Microneutralization (MN) Antibody Response for Each Homologous Strain Homologous (B/Brisbane/60/2008): Day 0	15.2 Titers Interval 13.8 to 16.7	14.9 Titers Interval 12.9 to 17.3
GMTs of Microneutralization (MN) Antibody Response for Each Homologous Strain Homologous (B/Brisbane/60/2008): Day 21	38.2 Titers Interval 34.3 to 42.7	16.0 Titers Interval 13.7 to 18.6
GMTs of Microneutralization (MN) Antibody Response for Each Homologous Strain Homologous (B/Phuket/3073/2013): Day 0	18.2 Titers Interval 16.3 to 20.4	18.9 Titers Interval 16.0 to 22.3
GMTs of Microneutralization (MN) Antibody Response for Each Homologous Strain Homologous (B/Phuket/3073/2013): Day 21	52.0 Titers Interval 46.1 to 58.6	21.3 Titers Interval 18.0 to 25.2

SECONDARY outcome

Timeframe: Day 0 (pre-vaccination) up to Day 21

Population: IPP Set

Seroconversion rate: the percentage of participants in a given treatment group with either a ≥ 4-fold increase in reciprocal MN titers between Day 0 and Day 21 or a rise of undetectable MN titer (i.e. 7.1) pre-vaccination (Day 0) to an MN titer of ≥ 28.3 at Day 21 post-vaccination were measured using an MN assay for homologous strains: H1 A/Michigan/45/2015 (H1N1), A/Hong Kong/4801/2014 (H3N2), B/Brisbane/60/2008, B/Phuket/3073/2013.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=278 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=97 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Percentage of Participants With Seroconversion Measured by MN Antibody Response for Each Homologous Strain Homologous (HIN1)	41.7 Percentage of Participants Interval 35.9 to 47.8	2.1 Percentage of Participants Interval 0.3 to 7.3
Percentage of Participants With Seroconversion Measured by MN Antibody Response for Each Homologous Strain Homologous (H3N2)	28.1 Percentage of Participants Interval 22.9 to 33.7	0 Percentage of Participants Interval 0.0 to 0.0
Percentage of Participants With Seroconversion Measured by MN Antibody Response for Each Homologous Strain Homologous (B/Brisbane/60/2008)	30.6 Percentage of Participants Interval 25.2 to 36.4	0 Percentage of Participants Interval 0.0 to 0.0
Percentage of Participants With Seroconversion Measured by MN Antibody Response for Each Homologous Strain Homologous (B/Phuket/3073/2013)	31.3 Percentage of Participants Interval 25.9 to 37.1	1.0 Percentage of Participants Interval 0.0 to 5.6

SECONDARY outcome

Timeframe: Day 0 (pre-vaccination), Day 21

Population: IPP Set

GMFR, the geometric mean of the ratio of GMTs (Day 21/Day 0) was measured in each treatment group using an MN assay for the homologous strains: H1 A/Michigan/45/2015 (H1N1), A/Hong Kong/4801/2014 (H3N2), B/Brisbane/60/2008, and B/Phuket/3073/2013.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=278 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=97 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
GMFR of MN Antibody Response for Each Homologous Strain Homologous (HIN1)	4.0 Ratio Interval 3.6 to 4.6	1.3 Ratio Interval 1.1 to 1.6
GMFR of MN Antibody Response for Each Homologous Strain Homologous (H3N2)	2.5 Ratio Interval 2.2 to 2.7	1.2 Ratio Interval 1.1 to 1.5
GMFR of MN Antibody Response for Each Homologous Strain Homologous (B/Brisbane/60/2008)	2.5 Ratio Interval 2.3 to 2.8	1.1 Ratio Interval 0.9 to 1.2
GMFR of MN Antibody Response for Each Homologous Strain Homologous (B/Phuket/3073/2013)	2.8 Ratio Interval 2.6 to 3.1	1.1 Ratio Interval 1.0 to 1.3

SECONDARY outcome

Timeframe: Day 0 (pre-vaccination), Day 21

Population: IPP Set

The GMA in each treatment group were measured using an SRH assay for homologous strains: H1 A/Michigan/45/2015 (H1N1), A/Hong Kong/4801/2014 (H3N2), B/Brisbane/60/2008, B/Phuket/3073/2013. The GMA calculations were performed by taking the anti-log of the mean of the log titer transformations.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=278 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=97 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Geometric Mean Area (GMA) of Single Radial Hemolysis (SRH) Antibody Response for Each Homologous Strain Homologous (HIN1): Day 0	10.3 mm^2 Interval 8.7 to 12.1	15.4 mm^2 Interval 12.0 to 19.8
Geometric Mean Area (GMA) of Single Radial Hemolysis (SRH) Antibody Response for Each Homologous Strain Homologous (HIN1): Day 21	31.4 mm^2 Interval 27.6 to 35.7	20.9 mm^2 Interval 16.4 to 26.6
Geometric Mean Area (GMA) of Single Radial Hemolysis (SRH) Antibody Response for Each Homologous Strain Homologous (H3N2): Day 0	15.6 mm^2 Interval 12.9 to 18.8	19.3 mm^2 Interval 14.2 to 26.1
Geometric Mean Area (GMA) of Single Radial Hemolysis (SRH) Antibody Response for Each Homologous Strain Homologous (H3N2): Day 21	56.0 mm^2 Interval 50.2 to 62.5	28.4 mm^2 Interval 21.2 to 38.1
Geometric Mean Area (GMA) of Single Radial Hemolysis (SRH) Antibody Response for Each Homologous Strain Homologous (B/Brisbane/60/2008): Day 0	8.2 mm^2 Interval 6.9 to 9.9	6.8 mm^2 Interval 5.0 to 9.3
Geometric Mean Area (GMA) of Single Radial Hemolysis (SRH) Antibody Response for Each Homologous Strain Homologous (B/Brisbane/60/2008): Day 21	31.9 mm^2 Interval 27.4 to 37.1	9.3 mm^2 Interval 6.7 to 12.9
Geometric Mean Area (GMA) of Single Radial Hemolysis (SRH) Antibody Response for Each Homologous Strain Homologous (B/Phuket/3073/2013): Day 0	11.4 mm^2 Interval 9.5 to 13.7	11.7 mm^2 Interval 8.8 to 15.7
Geometric Mean Area (GMA) of Single Radial Hemolysis (SRH) Antibody Response for Each Homologous Strain Homologous (B/Phuket/3073/2013): Day 21	36.7 mm^2 Interval 31.9 to 42.1	15.5 mm^2 Interval 11.5 to 20.8

SECONDARY outcome

Timeframe: Day 0 (pre-vaccination) up to Day 21

Population: IPP Set

Seroconversion rate: the percentage of participants in a given treatment group showing at least 50 % increase in GMA between Days 0 and 21 were measured using a SRH assay for homologous strains: H1 A/Michigan/45/2015 (H1N1), A/Hong Kong/4801/2014 (H3N2), B/Brisbane/60/2008, B/Phuket/3073/2013.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=278 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=97 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Percentage of Participants With Seroconversion Measured by SRH Antibody Response for Each Homologous Strain Homologous (HIN1)	53.6 Percentage of Participants Interval 47.5 to 59.6	14.4 Percentage of Participants Interval 8.1 to 23.0
Percentage of Participants With Seroconversion Measured by SRH Antibody Response for Each Homologous Strain Homologous (H3N2)	48.2 Percentage of Participants Interval 42.2 to 54.2	14.4 Percentage of Participants Interval 8.1 to 23.0
Percentage of Participants With Seroconversion Measured by SRH Antibody Response for Each Homologous Strain Homologous (B/Brisbane/60/2008)	45.7 Percentage of Participants Interval 39.7 to 51.7	9.3 Percentage of Participants Interval 4.3 to 16.9
Percentage of Participants With Seroconversion Measured by SRH Antibody Response for Each Homologous Strain Homologous (B/Phuket/3073/2013)	47.1 Percentage of Participants Interval 41.1 to 53.2	12.4 Percentage of Participants Interval 6.6 to 20.6

SECONDARY outcome

Timeframe: Day 0 (pre-vaccination) up to Day 21

Population: IPP Set

Seroprotection rate: the percentage of participants in a given treatment group attaining an area ≥ 25 mm\^2 following vaccination (Day 21) were measured using an SRH assay for homologous strains: H1 A/Michigan/45/2015 (H1N1), A/Hong Kong/4801/2014 (H3N2), B/Brisbane/60/2008, B/Phuket/3073/2013.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=278 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=97 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
Percentage of Participants With Seroprotection Measured by SRH Antibody Response for Each Homologous Strain Homologous (HIN1): Day 0	36.3 Percentage of Participants Interval 30.7 to 42.3	42.3 Percentage of Participants Interval 32.3 to 52.7
Percentage of Participants With Seroprotection Measured by SRH Antibody Response for Each Homologous Strain Homologous (HIN1): Day 21	75.9 Percentage of Participants Interval 70.4 to 80.8	57.7 Percentage of Participants Interval 47.3 to 67.7
Percentage of Participants With Seroprotection Measured by SRH Antibody Response for Each Homologous Strain Homologous (H3N2): Day 0	54.7 Percentage of Participants Interval 48.6 to 60.6	57.7 Percentage of Participants Interval 47.3 to 67.7
Percentage of Participants With Seroprotection Measured by SRH Antibody Response for Each Homologous Strain Homologous (H3N2): Day 21	92.1 Percentage of Participants Interval 88.3 to 95.0	74.2 Percentage of Participants Interval 64.3 to 82.6
Percentage of Participants With Seroprotection Measured by SRH Antibody Response for Each Homologous Strain Homologous (B/Brisbane/60/2008): Day 0	40.3 Percentage of Participants Interval 34.5 to 46.3	37.1 Percentage of Participants Interval 27.5 to 47.5
Percentage of Participants With Seroprotection Measured by SRH Antibody Response for Each Homologous Strain Homologous (B/Brisbane/60/2008): Day 21	81.3 Percentage of Participants Interval 76.2 to 85.7	45.4 Percentage of Participants Interval 35.2 to 55.8
Percentage of Participants With Seroprotection Measured by SRH Antibody Response for Each Homologous Strain Homologous (B/Phuket/3073/2013): Day 0	47.5 Percentage of Participants Interval 41.5 to 53.5	44.3 Percentage of Participants Interval 34.2 to 54.8
Percentage of Participants With Seroprotection Measured by SRH Antibody Response for Each Homologous Strain Homologous (B/Phuket/3073/2013): Day 21	81.7 Percentage of Participants Interval 76.6 to 86.0	54.6 Percentage of Participants Interval 44.2 to 64.8

SECONDARY outcome

Timeframe: Day 0 (pre-vaccination), Day 21

Population: IPP Set

GMFR, the geometric mean of the ratio of GMTs (Day 21/Day 0) was measured in each treatment group using an SRH assay for the homologous strains: H1 A/Michigan/45/2015 (H1N1), A/Hong Kong/4801/2014 (H3N2), B/Brisbane/60/2008, and B/Phuket/3073/2013.

Outcome measures

Outcome measures
Measure	Quadrivalent VLP Vaccine n=278 Participants Participants received one IM injection of 0.5 mL of 30 μg/strain of the Quadrivalent VLP Influenza Vaccine on Day 0.	Placebo n=97 Participants Participants received one IM injection of 0.5 mL of placebo on Day 0.
GMFR of SRH Antibody Response for Each Homologous Strain Homologous (HIN1)	2.9 Ratio Interval 2.6 to 3.2	1.6 Ratio Interval 1.3 to 1.9
GMFR of SRH Antibody Response for Each Homologous Strain Homologous (H3N2)	3.5 Ratio Interval 3.1 to 3.9	1.6 Ratio Interval 1.4 to 2.0
GMFR of SRH Antibody Response for Each Homologous Strain Homologous (B/Brisbane/60/2008)	4.0 Ratio Interval 3.5 to 4.5	1.3 Ratio Interval 1.0 to 1.6
GMFR of SRH Antibody Response for Each Homologous Strain Homologous (B/Phuket/3073/2013)	3.2 Ratio Interval 2.9 to 3.6	1.3 Ratio Interval 1.1 to 1.6

Adverse Events

Quadrivalent VLP Vaccine

Serious events: 55 serious events

Other events: 930 other events

Deaths: 1 deaths

Placebo

Serious events: 51 serious events

Other events: 918 other events

Deaths: 2 deaths

Serious adverse events

Other adverse events

Additional Information

Medical Director

Medicago

Phone: +1 418-658-9393

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee The Investigator understands that the information in the protocol is confidential and should not be disclosed, other than to those directly involved in the execution or the ethical review of the study, without prior written authorization from the Sponsor. It is, however, permissible to discuss information contained in the protocol with a participant in order to obtain consent once Institutional Review Board (IRB) approval is obtained.
Publication restrictions are in place

Restriction type: OTHER