A Phase 2 interventional study of Experimental: IIV-A Investigational IIV-A administered as a single dose intramuscularly on Day 1 and Experimental: aIIV-B Investigational aIIV-B administered as a single dose intramuscularly on Day 1 in Influenza, Human, sponsored by Seqirus. Completed at 47 sites in United States. Open to participants aged 50 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-06-30.
Sponsored by Seqirus (part of CSL Limited) · Phase 2, Interventional, and Prevention
This Phase 2, randomized, observer-blind, dose-confirmation clinical study evaluated different formulations of MF59-Adjuvanted Quadrivalent Subunit Inactivated Influenza Vaccine. Approximately 1000 subjects were randomized into 1 of 4 possible treatment groups with approximately 250 participants per group. Every participant received an influenza vaccine injection on Day 1 and were to be followed up for approximately 6 months following injection. The primary immunogenicity analysis is based on Day 29 serology data.
2,356 studies on the registry are indexed under Influenza, Human; 184 are open to participants now.
This study's enrollment of 1,056 is above the median of 227 across 1,957 interventional studies indexed under Influenza, Human.
Browse Influenza, Human studies →Seqirus is the lead sponsor of 53 studies on the registry; none are open to participants now.
Of its 15 completed or terminated interventional studies of FDA-regulated products, 10 (67%) have results posted.
First submitted after Seqirus became part of CSL Limited.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
In order to participate in this study, all subjects must meet ALL of the inclusion criteria described.
Males, females of non- or females of childbearing potential who are using an effective method, at least 30 days prior to informed consent, which they intend to use for at least 2 months after the study vaccination.
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Exclusion Criteria:
In order to participate in this study, all subjects must not meet ANY of the exclusion criteria described below:
Abnormal function of the immune system resulting from:
Any other clinical condition that, in the opinion of the investigator, might interfere with the results of the study or pose additional risk to the subject due to participation in the study.
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Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Live vaccines
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biological: Experimental: IIV-A Investigational IIV-A administered as a single dose intramuscularly on Day 1
Biological: Experimental: aIIV-B Investigational aIIV-B administered as a single dose intramuscularly on Day 1
Biological: Experimental: aIIV-C Investigational aIIV-C administered as a single dose intramuscularly on Day 1
Biological: Active Comparator: Licensed IIV IIV administered as a single dose intramuscularly on Day 1
Biological/Vaccine: Investigational IIV-A Investigational Quadrivalent Influenza vaccine (higher hemagglutinin \[HA\] dose), containing four influenza virus strains (A/H1N1, A/H3N2, B/Yamagata and Victoria lineage) recommended by the WHO (World Health Organization) for quadrivalent vaccines for the respective season.
Biological/Vaccine: Investigational aIIV-B Investigational MF59 Adjuvanted Quadrivalent Influenza vaccine (higher HA dose, standard dose MF59), containing four influenza virus strains (A/H1N1, A/H3N2, B/Yamagata and Victoria lineage) recommended by the WHO (World Health Organization) for quadrivalent vaccines for the respective season.
Biological/Vaccine: Investigational aIIV-C Investigational MF59 Adjuvanted Quadrivalent Influenza vaccine (higher HA dose, higher dose MF59), containing four influenza virus strains (A/H1N1, A/H3N2, B/Yamagata and Victoria lineage) recommended by the WHO (World Health Organization) for quadrivalent vaccines for the respective season.
Biological/Vaccine: Licensed IIV Licensed Non-adjuvanted Quadrivalent Influenza vaccine (standard HA dose), containing four influenza virus strains (A/H1N1, A/H3N2, B/Yamagata and Victoria lineage) recommended by the WHO (World Health Organization) for quadrivalent vaccines for the respective season.
Immunogenicity Endpoint: Geometric Mean Titer (GMT): Geometric Mean of Hemagglutination Inhibition (HI) Antibodies at Day 1 and Day 29
GMTs on Day 1 (prior to vaccination) and Day 29 as determined by HI assay against each of the 4 vaccine strains. No hypothesis testing was performed for the primary immunogenicity objectives.
Time frame: Day 1 and Day 29
Immunogenicity Endpoint: Geometric Mean Fold Increase (GMFI) (HI Assay)
Geometric mean of the fold increase in serum HI titer postvaccination (Day 29) compared to prevaccination (Day 1) for each of the 4 vaccine strains.
Time frame: Day 1 to Day 29
Immunogenicity Endpoint: Percentages of Subjects With HI Titers ≥1:40 at Day 1 and Day 29
Percentages of subjects with HI titers ≥1:40 at Day 1 and Day 29 for each of the 4 vaccine strains.
Time frame: Day 1 and Day 29
Immunogenicity Endpoint: Percentage of Subjects With Seroconversion at Day 29 (HI Assay)
Seroconversion is defined as ≥4-fold increase in titer postvaccination in those with prevaccination titer equal to or above the lower limit of quantitation (LLOQ; 1:10), or a postvaccination titer ≥1:40 for subjects with baseline titer below the LLOQ (1:10) for HI antibodies.
Time frame: Day 1 to Day 29
Immunogenicity Endpoint: GMT Ratio (HI Assay)
The GMT ratio is the geometric mean of the postvaccination HI titer for the investigational vaccine over the geometric mean of the postvaccination HI titer for the licensed IIV vaccine. The Day 29 GMT ratios are calculated for the investigational vaccines with reference to the licensed vaccine, ie, the Day 29 GMT ratios are the ratio of the Day 29 GMTs in the Investigational group (IIV-A Investigational, aIIV-B Investigational, or aIIV-C Investigational) compared with the Day 29 GMTs in the Licensed IIV group (ie, Investigational group/Licensed IIV group). As the licensed vaccine is the reference for the GMT ratio, this parameter is presented as "1" for the Licensed IIV group (ie, Licensed IIV group/Licensed IIV group).
Time frame: Day 29
Solicited Local or Systemic AEs
Number and percentage of subjects with solicited local or systemic AEs for 7 days following vaccination, based on the subject reported data (electronic Diary \[eDiary\]). No hypothesis testing was performed for the primary safety objectives.
Time frame: Day 1 through Day 7
Severe Solicited Local or Systemic AEs
Number and percentage of subjects with severe solicited local or systemic AEs for 7 days following vaccination, based on the subject reported data (eDiary).
Time frame: Day 1 through Day 7
Unsolicited AEs
Number and percentage of subjects with unsolicited AEs for 28 days following vaccination
Time frame: Day 1 to Day 29
Subjects With Serious Adverse Events (SAEs), AEs Leading to Withdrawal, Adverse Events of Special Interest (AESIs) and Medically-attended Adverse Events (MAAEs)
Number and percentage of subjects with SAEs, AEs leading to withdrawal from the study, AESIs and non-serious MAAEs
Time frame: Day 1 to Day 181
Immunogenicity Endpoint: GMT: Geometric Mean of Microneutralization (MN) Antibodies Titer at Days 1 and 29
GMTs on Day 1 (prior to vaccination) and Day 29 as determined by MN assay against each of the 4 vaccine strains.
Time frame: Day 1 and Day 29
Immunogenicity Endpoint: GMFI (MN Assay)
Geometric mean of the fold increase in serum MN titer postvaccination (Day 29) compared to prevaccination (Day 1) for each of the 4 vaccine strains.
Time frame: Day 1 to Day 29
Immunogenicity Endpoint: Percentages of Subjects With Seroconversion at Day 29 (MN Assay)
Seroconversion is defined as ≥4-fold increase for subjects with prevaccination MN titers ≥LLOQ (1:10) or as ≥4\*LLOQ (1:10) for subjects with prevaccination MN titer \<LLOQ.
Time frame: Day 1 to Day 29
Immunogenicity Endpoint: GMT Ratio (MN Assay)
The GMT ratio is the geometric mean of the postvaccination HI titer for the investigational vaccine over the geometric mean of the postvaccination HI titer for the licensed IIV vaccine. The Day 29 GMT ratios are calculated for the investigational vaccines with reference to the licensed vaccine, ie, the Day 29 GMT ratios are the ratio of the Day 29 GMTs in the Investigational group (IIV-A Investigational, aIIV-B Investigational, or aIIV-C Investigational) compared with the Day 29 GMTs in the Licensed IIV group (ie, Investigational group/Licensed IIV group). As the licensed vaccine is the reference for the GMT ratio, this parameter is presented as "1" for the Licensed IIV group (ie, Licensed IIV group/Licensed IIV group).
Time frame: Day 29
| Milestone | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV |
|---|---|---|---|---|
| Started | 264 | 265 | 264 | 263 |
| Completed | 255 | 252 | 253 | 254 |
| Not completed | 9 | 13 | 11 | 9 |
| Withdrew: Death | 0 | 0 | 1 | 0 |
| Withdrew: Withdrawal by subject | 1 | 4 | 2 | 4 |
| Withdrew: Lost to follow-up | 8 | 9 | 7 | 4 |
| Withdrew: Other | 0 | 0 | 1 | 1 |
GMTs on Day 1 (prior to vaccination) and Day 29 as determined by HI assay against each of the 4 vaccine strains. No hypothesis testing was performed for the primary immunogenicity objectives.
| Geometric mean titer | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV |
|---|---|---|---|---|
| A/H1N1 Day 1 HI GMT | 29.79 (25.54 to 34.74) | 33.09 (28.39 to 38.56) | 31.78 (27.26 to 37.04) | 39.29 (33.63 to 45.90) |
| A/H1N1 Day 29 HI GMT | 286.95 (248.32 to 331.60) | 302.30 (261.92 to 348.92) | 369.57 (320.08 to 426.71) | 198.84 (171.89 to 230.02) |
| A/H3N2 Day 1 HI GMT | 37.81 (32.89 to 43.46) | 35.11 (30.57 to 40.32) | 43.33 (37.72 to 49.78) | 39.80 (34.57 to 45.82) |
| A/H3N2 Day 29 HI GMT | 140.71 (124.12 to 159.52) | 149.75 (132.15 to 169.69) | 171.38 (151.25 to 194.18) | 133.43 (117.54 to 151.47) |
| B/Yamagata Day 1 HI GMT | 11.18 (10.07 to 12.40) | 10.49 (9.45 to 11.63) | 11.08 (9.99 to 12.29) | 11.03 (9.93 to 12.25) |
| B/Yamagata Day 29 HI GMT | 35.11 (31.49 to 39.15) | 38.58 (34.61 to 43.00) | 51.61 (46.30 to 57.53) | 31.40 (28.12 to 35.06) |
| B/Victoria Day 1 HI GMT | 27.39 (23.77 to 31.57) | 29.35 (25.48 to 33.79) | 32.05 (27.83 to 36.92) | 34.57 (29.94 to 39.90) |
| B/Victoria Day 29 HI GMT | 210.22 (181.58 to 243.38) | 200.86 (173.70 to 232.27) | 232.61 (201.17 to 268.96) | 183.28 (158.18 to 212.37) |
Geometric mean of the fold increase in serum HI titer postvaccination (Day 29) compared to prevaccination (Day 1) for each of the 4 vaccine strains.
| Geometric mean fold increase | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV |
|---|---|---|---|---|
| A/H1N1 HI GMFI (Day 29/Day 1) | 8.57 (7.28 to 10.08) | 8.57 (7.29 to 10.08) | 10.69 (9.09 to 12.57) | 5.18 (4.40 to 6.11) |
| A/H3N2 HI GMFI (Day 29/Day 1) | 3.54 (3.08 to 4.08) | 3.90 (3.39 to 4.48) | 4.06 (3.53 to 4.67) | 3.28 (2.85 to 3.78) |
| B/Yamagata HI GMFI (Day 29/Day 1) | 3.08 (2.75 to 3.45) | 3.46 (3.09 to 3.88) | 4.54 (4.05 to 5.09) | 2.77 (2.46 to 3.11) |
| B/Victoria HI GMFI (Day 29/Day 1) | 6.71 (5.72 to 7.86) | 6.21 (5.31 to 7.28) | 6.92 (5.91 to 8.11) | 5.27 (4.49 to 6.19) |
Percentages of subjects with HI titers ≥1:40 at Day 1 and Day 29 for each of the 4 vaccine strains.
| Percentage of participants | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV |
|---|---|---|---|---|
| A/H1N1 HI titer ≥1:40 at Day 1 | 53.9 (47.6 to 60.1) | 55.6 (49.3 to 61.8) | 54.8 (48.5 to 61.0) | 62.0 (55.7 to 68.0) |
| A/H1N1 HI titer ≥1:40 at Day 29 | 93.4 (89.6 to 96.1) | 93.0 (89.2 to 95.8) | 95.0 (91.6 to 97.3) | 92.0 (87.9 to 95.0) |
| A/H3N2 HI titer ≥1:40 at Day 1 | 57.0 (50.7 to 63.2) | 54.9 (48.6 to 61.1) | 60.6 (54.4 to 66.6) | 61.6 (55.3 to 67.7) |
| A/H3N2 HI titer ≥1:40 at Day 29 | 92.6 (88.7 to 95.5) | 91.8 (87.8 to 94.9) | 94.2 (90.6 to 96.7) | 88.4 (83.8 to 92.1) |
| B/Yamagata HI titer ≥1:40 at Day 1 | 14.5 (10.4 to 19.4) | 11.7 (8.0 to 16.2) | 13.5 (9.6 to 18.3) | 14.0 (9.9 to 18.9) |
| B/Yamagata HI titer ≥1:40 at Day 29 | 51.6 (45.3 to 57.8) | 52.9 (46.6 to 59.2) | 66.4 (60.3 to 72.1) | 51.2 (44.8 to 57.5) |
| B/Victoria HI titer ≥1:40 at Day 1 | 48.8 (42.6 to 55.1) | 51.8 (45.5 to 58.0) | 52.9 (46.6 to 59.1) | 56.8 (50.4 to 63.0) |
| B/Victoria HI titer ≥1:40 at Day 29 | 90.6 (86.4 to 93.9) | 92.2 (88.2 to 95.2) | 93.8 (90.2 to 96.4) | 92.4 (88.4 to 95.4) |
Seroconversion is defined as ≥4-fold increase in titer postvaccination in those with prevaccination titer equal to or above the lower limit of quantitation (LLOQ; 1:10), or a postvaccination titer ≥1:40 for subjects with baseline titer below the LLOQ (1:10) for HI antibodies.
| Percentage of participants | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV |
|---|---|---|---|---|
| A/H1N1 Seroconversion at Day 29 | 63.3 (57.1 to 69.2) | 63.0 (56.8 to 69.0) | 68.7 (62.7 to 74.3) | 45.2 (38.9 to 51.6) |
| A/H3N2 Seroconversion at Day 29 | 42.6 (36.4 to 48.9) | 44.7 (38.6 to 51.1) | 45.9 (39.8 to 52.2) | 39.2 (33.1 to 45.6) |
| B/Yamagata Seroconversion at Day 29 | 28.9 (23.4 to 34.9) | 36.2 (30.3 to 42.4) | 44.8 (38.6 to 51.1) | 25.6 (20.3 to 31.5) |
| B/Victoria Seroconversion at Day 29 | 58.6 (52.3 to 64.7) | 53.7 (47.4 to 59.9) | 60.2 (54.0 to 66.2) | 42.8 (36.6 to 49.2) |
The GMT ratio is the geometric mean of the postvaccination HI titer for the investigational vaccine over the geometric mean of the postvaccination HI titer for the licensed IIV vaccine. The Day 29 GMT ratios are calculated for the investigational vaccines with reference to the licensed vaccine, ie, the Day 29 GMT ratios are the ratio of the Day 29 GMTs in the Investigational group (IIV-A Investigational, aIIV-B Investigational, or aIIV-C Investigational) compared with the Day 29 GMTs in the Licensed IIV group (ie, Investigational group/Licensed IIV group). As the licensed vaccine is the reference for the GMT ratio, this parameter is presented as "1" for the Licensed IIV group (ie, Licensed IIV group/Licensed IIV group).
| GMT ratio | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV |
|---|---|---|---|---|
| A/H1N1 Day 29 HI GMT Ratio | 1.44 (1.18 to 1.76) | 1.52 (1.25 to 1.85) | 1.86 (1.52 to 2.27) | 1 (NA to NA) |
| A/H3N2 Day 29 HI GMT Ratio | 1.05 (0.89 to 1.25) | 1.12 (0.94 to 1.33) | 1.28 (1.08 to 1.53) | 1 (NA to NA) |
| B/Yamagata Day 29 HI GMT Ratio | 1.12 (0.96 to 1.30) | 1.23 (1.06 to 1.43) | 1.64 (1.42 to 1.91) | 1 (NA to NA) |
| B/Victoria Day 29 HI GMT Ratio | 1.15 (0.94 to 1.40) | 1.10 (0.90 to 1.34) | 1.27 (1.04 to 1.55) | 1 (NA to NA) |
Number and percentage of subjects with solicited local or systemic AEs for 7 days following vaccination, based on the subject reported data (electronic Diary \[eDiary\]). No hypothesis testing was performed for the primary safety objectives.
| Participants | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV |
|---|---|---|---|---|
| Any solicited AE | 148 | 146 | 177 | 126 |
| Any local solicited AE | 94 | 116 | 146 | 59 |
| Any systemic solicited AE | 117 | 93 | 124 | 107 |
| Use of antipyretic/analgesics | 33 | 36 | 51 | 33 |
Number and percentage of subjects with severe solicited local or systemic AEs for 7 days following vaccination, based on the subject reported data (eDiary).
| Participants | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV |
|---|---|---|---|---|
| Severe solicited local AEs | 6 | 2 | 5 | 1 |
| Severe solicited systemic AEs | 8 | 2 | 10 | 2 |
Number and percentage of subjects with unsolicited AEs for 28 days following vaccination
| Participants | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV |
|---|---|---|---|---|
| Any unsolicited AE | 30 | 10 | 24 | 24 |
| Any related unsolicited AE | 9 | 2 | 7 | 5 |
Number and percentage of subjects with SAEs, AEs leading to withdrawal from the study, AESIs and non-serious MAAEs
| Participants | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV |
|---|---|---|---|---|
| Any SAE | 8 | 5 | 4 | 10 |
| Any related SAE | 0 | 1 | 0 | 0 |
| Any AE leading to withdrawal | 0 | 0 | 1 | 0 |
| Any AESI | 0 | 0 | 0 | 0 |
| Any non-serious MAAE | 27 | 33 | 38 | 42 |
GMTs on Day 1 (prior to vaccination) and Day 29 as determined by MN assay against each of the 4 vaccine strains.
| Geometric mean titer | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV |
|---|---|---|---|---|
| A/H1N1 Day 1 MN GMT | 159.95 (144.14 to 177.51) | 152.69 (137.67 to 169.36) | 172.00 (155.05 to 190.80) | 174.39 (156.96 to 193.76) |
| A/H1N1 Day 29 MN GMT | 603.49 (539.24 to 675.38) | 661.34 (591.17 to 739.84) | 759.48 (679.03 to 849.47) | 475.49 (424.40 to 532.73) |
| A/H3N2 Day 1 MN GMT | 28.43 (24.54 to 32.94) | 28.99 (25.04 to 33.56) | 31.31 (27.04 to 36.26) | 29.94 (25.80 to 34.75) |
| A/H3N2 Day 29 MN GMT | 125.78 (110.91 to 142.65) | 134.63 (118.79 to 152.58) | 158.37 (139.71 to 179.52) | 105.67 (93.04 to 120.01) |
| B/Yamagata Day 1 MN GMT | 99.60 (89.35 to 111.03) | 107.12 (96.15 to 119.34) | 106.24 (95.34 to 118.37) | 100.57 (90.11 to 112.24) |
| B/Yamagata Day 29 MN GMT | 319.34 (287.79 to 354.35) | 315.46 (284.51 to 349.77) | 417.80 (376.74 to 463.33) | 274.34 (246.95 to 304.77) |
| B/Victoria Day 1 MN GMT | 176.85 (152.08 to 205.65) | 202.90 (174.62 to 235.75) | 195.97 (168.62 to 227.75) | 215.80 (185.26 to 251.37) |
| B/Victoria Day 29 MN GMT | 1747.02 (1508.87 to 2022.77) | 1771.75 (1532.35 to 2048.54) | 2181.94 (1886.48 to 2523.68) | 1451.90 (1252.81 to 1682.61) |
Geometric mean of the fold increase in serum MN titer postvaccination (Day 29) compared to prevaccination (Day 1) for each of the 4 vaccine strains.
| Geometric mean fold increase | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV |
|---|---|---|---|---|
| A/H1N1 MN GMFI (Day 29/Day 1) | 3.59 (3.18 to 4.05) | 4.01 (3.56 to 4.53) | 4.37 (3.87 to 4.93) | 2.72 (2.41 to 3.08) |
| A/H3N2 MN GMFI (Day 29/Day 1) | 4.21 (3.70 to 4.79) | 4.48 (3.94 to 5.10) | 5.19 (4.56 to 5.91) | 3.50 (3.07 to 3.99) |
| B/Yamagata MN GMFI (Day 29/Day 1) | 2.94 (2.64 to 3.29) | 2.84 (2.54 to 3.16) | 3.77 (3.38 to 4.20) | 2.52 (2.25 to 2.82) |
| B/Victoria MN GMFI (Day 29/Day 1) | 8.91 (7.51 to 10.56) | 8.33 (7.03 to 9.87) | 10.47 (8.84 to 12.41) | 6.59 (5.54 to 7.83) |
Seroconversion is defined as ≥4-fold increase for subjects with prevaccination MN titers ≥LLOQ (1:10) or as ≥4\*LLOQ (1:10) for subjects with prevaccination MN titer \<LLOQ.
| Percentage of participants | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV |
|---|---|---|---|---|
| A/H1N1 Seroconversion at Day 29 | 37.5 (31.5 to 43.7) | 40.5 (34.4 to 46.7) | 44.0 (37.9 to 50.3) | 24.0 (18.8 to 29.8) |
| A/H3N2 Seroconversion at Day 29 | 46.9 (40.6 to 53.2) | 49.4 (43.1 to 55.7) | 58.7 (52.4 to 64.7) | 41.2 (35.0 to 47.6) |
| B/Yamagata Seroconversion at Day 29 | 28.9 (23.4 to 34.9) | 26.1 (20.8 to 31.9) | 42.1 (36.0 to 48.4) | 22.8 (17.7 to 28.5) |
| B/Victoria Seroconversion at Day 29 | 64.8 (58.7 to 70.7) | 60.3 (54.0 to 66.3) | 70.7 (64.7 to 76.1) | 50.0 (43.6 to 56.4) |
The GMT ratio is the geometric mean of the postvaccination HI titer for the investigational vaccine over the geometric mean of the postvaccination HI titer for the licensed IIV vaccine. The Day 29 GMT ratios are calculated for the investigational vaccines with reference to the licensed vaccine, ie, the Day 29 GMT ratios are the ratio of the Day 29 GMTs in the Investigational group (IIV-A Investigational, aIIV-B Investigational, or aIIV-C Investigational) compared with the Day 29 GMTs in the Licensed IIV group (ie, Investigational group/Licensed IIV group). As the licensed vaccine is the reference for the GMT ratio, this parameter is presented as "1" for the Licensed IIV group (ie, Licensed IIV group/Licensed IIV group).
| GMT ratio | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV |
|---|---|---|---|---|
| A/H1N1 Day 29 MN GMT Ratio | 1.27 (1.09 to 1.48) | 1.39 (1.19 to 1.62) | 1.60 (1.37 to 1.86) | 1 (NA to NA) |
| A/H3N2 Day 29 MN GMT Ratio | 1.19 (1.00 to 1.42) | 1.27 (1.07 to 1.51) | 1.50 (1.26 to 1.78) | 1 (NA to NA) |
| B/Yamagata Day 29 MN GMT Ratio | 1.16 (1.01 to 1.34) | 1.15 (1.00 to 1.33) | 1.52 (1.32 to 1.76) | 1 (NA to NA) |
| B/Victoria Day 29 MN GMT Ratio | 1.20 (0.98 to 1.47) | 1.22 (1.00 to 1.49) | 1.50 (1.23 to 1.84) | 1 (NA to NA) |
Collected over All-Cause Mortality, SAEs, AEs leading to withdrawal from the study, AESIs and non-serious MAAEs are reported from Day 1 to Day 181; all unsolicited AEs are reported from Day 1 to Day 29. Solicited AEs are reported from Day 1 to Day 7.. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| IIV-A Investigational | 0/264 (0%) | 8/264 (3%) | 161/264 (61%) |
| aIIV-B Investigational | 0/263 (0%) | 5/263 (1.9%) | 162/263 (61.6%) |
| aIIV-C Investigational | 1/262 (0.4%) | 4/262 (1.5%) | 190/262 (72.5%) |
| Licensed IIV | 0/262 (0%) | 10/262 (3.8%) | 141/262 (53.8%) |
| Event | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV |
|---|---|---|---|---|
| Chronic obstructive pulmonary diseaseRespiratory, thoracic and mediastinal disorders | 1/264 | 0/263 | 0/262 | 2/262 |
| Acute cardiac eventCardiac disorders | 0/264 | 0/263 | 1/262 | 0/262 |
| Acute coronary syndromeCardiac disorders | 0/264 | 0/263 | 0/262 | 1/262 |
| IleusGastrointestinal disorders | 0/264 | 0/263 | 0/262 | 1/262 |
| Non-cardiac chest painGeneral disorders | 0/264 | 0/263 | 0/262 | 1/262 |
| Hepatic cirrhosisHepatobiliary disorders | 0/264 | 0/263 | 0/262 | 1/262 |
| InfluenzaInfections and infestations | 1/264 | 0/263 | 0/262 | 1/262 |
| CellulitisInfections and infestations | 0/264 | 0/263 | 0/262 | 1/262 |
| CystitisInfections and infestations | 0/264 | 0/263 | 0/262 | 1/262 |
| Pneumonia pneumococcalInfections and infestations | 0/264 | 0/263 | 0/262 | 1/262 |
| Event | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV |
|---|---|---|---|---|
| Injection Site PainGeneral disorders | 89/264 | 112/263 | 145/262 | 55/262 |
| FatigueGeneral disorders | 89/264 | 75/263 | 102/262 | 78/262 |
| HeadacheNervous system disorders | 62/264 | 48/263 | 50/262 | 52/262 |
| MyalgiaMusculoskeletal and connective tissue disorders | 36/264 | 35/263 | 50/262 | 29/262 |
| ArthralgiaMusculoskeletal and connective tissue disorders | 32/264 | 22/263 | 38/262 | 24/262 |
| IndurationSkin and subcutaneous tissue disorders | 9/264 | 12/263 | 23/262 | 4/262 |
| NauseaGastrointestinal disorders | 13/264 | 16/263 | 19/262 | 11/262 |
| ErythemaSkin and subcutaneous tissue disorders | 12/264 | 11/263 | 16/262 | 7/262 |
| Age, Continuous(years) | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV | Total |
|---|---|---|---|---|---|
| Mean | 64.5 ± 9.14 | 64.0 ± 8.50 | 64.1 ± 8.99 | 63.9 ± 7.88 | 64.1 ± 8.63 |
| Age, Customized(Participants) | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV | Total |
|---|---|---|---|---|---|
| 50 to 64 years | 139 | 138 | 137 | 136 | 550 |
| ≥65 years | 125 | 127 | 127 | 127 | 506 |
| Sex: Female, Male(Participants) | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV | Total |
|---|---|---|---|---|---|
| Female | 154 | 154 | 155 | 149 | 612 |
| Male | 110 | 111 | 109 | 114 | 444 |
| Ethnicity (NIH/OMB)(Participants) | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV | Total |
|---|---|---|---|---|---|
| Hispanic or Latino | 29 | 22 | 22 | 28 | 101 |
| Not Hispanic or Latino | 235 | 243 | 238 | 234 | 950 |
| Unknown or Not Reported | 0 | 0 | 4 | 1 | 5 |
| Race/Ethnicity, Customized(Participants) | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV | Total |
|---|---|---|---|---|---|
| White | 224 | 213 | 229 | 218 | 884 |
| Black or African American | 38 | 47 | 28 | 38 | 151 |
| Asian | 1 | 2 | 4 | 3 | 10 |
| American Indian or Alaska Native | 0 | 2 | 1 | 2 | 5 |
| Native Hawaiian or Pacific Islander | 0 | 1 | 0 | 0 | 1 |
| Other | 1 | 0 | 2 | 2 | 5 |
| Body mass index(kg/m^2) | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV | Total |
|---|---|---|---|---|---|
| Mean | 30.35 ± 6.552 | 30.89 ± 7.380 | 30.69 ± 6.818 | 31.25 ± 6.758 | 30.80 ± 6.883 |
| Vaccinated within 3 previous influenza seasons(Participants) | IIV-A Investigational | aIIV-B Investigational | aIIV-C Investigational | Licensed IIV | Total |
|---|---|---|---|---|---|
| Yes | 190 | 188 | 194 | 188 | 760 |
| No | 74 | 77 | 70 | 75 | 296 |
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: Yes — SEQIRUS supports the release of anonymized subject-level and study-level data in compliance with regulatory requirements, including Clinical Documents which are part of the CTD modules submitted to regulatory agencies for public release. Summary results disclosure is either in document form (e.g., ICH E3 Clinical Study Report synopsis) or structured data form (such as summary results in ClinicalTrials.gov (United States) or eudract.ema.europa.eu (EU Clinical Trial Registry [EU CTR])
Supporting information: Study protocol, Statistical analysis plan
Time frame: SEQIRUS discloses results from clinical studies within 12 months of completion of the study unless otherwise mandated by local laws or regulations.
Access criteria: SEQIRUS will consider requests from qualified scientific and medical researchers to disclose protocols, anonymized subject-level data and study-level data when there is medical, scientific and/or public health interest to ensure the safe use of a Seqirus product licensed on or after 1 January 2014 in the United States (US) and/or the European Union (EU). This applies to Seqirus-sponsored interventional studies initiated after 27 September 2007 and ongoing as of 26 December 2007, that have been included as part of a US or EU submission package which received approval in US and EU on or after 1 January 2014 and have been accepted for publication
Data sharing details ↗ · www.seqirus.us
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