Influenza, HumanPhase 1NCT05875961
Study to Evaluate Immunogenicity, Safety and Tolerability of Adjuvanted and Non-Adjuvanted H2N3 Influenza Vaccines in Adults
A Phase 1 study testing Low dose A/H2N3c + standard dose MF59, Intermediate dose A/H2N3c + standard dose MF59 and High dose A/H2N3c + standard dose MF59 in people with Influenza, Human and Infections, run by Seqirus at 7 sites in 2 countries.
Trial summary
This Phase 1, randomized, observer-blind, dose-ranging clinical study is evaluating 6 different formulations of MF59-adjuvanted and non-adjuvanted H2N3 influenza vaccine. Approximately 600 healthy adult subjects are to be randomized into 1 of 6 possible treatment groups with 100 subjects per group, stratified by age… Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Influenza, Human, Infections, Respiratory Tract Infections
- What is being tested?
- Low dose A/H2N3c + standard dose MF59, Intermediate dose A/H2N3c + standard dose MF59 and High dose A/H2N3c + standard dose MF59
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 600 participants
- Where
- 7 sitesin 2 countries
- Study dates
- 15 Jun 2023to 15 Nov 2024
- Phase
- Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Individuals of 18 years of age and older on the day of informed consent who were not born in 1968.
- Individuals who have voluntarily given written informed consent after the nature of the study has been explained according to local regulatory requirements, prior to study entry.
- Individuals who can comply with study procedures including follow-up.
- Males, females of non-childbearing potential or females of childbearing potential who are using an effective birth control method, at least 30 days prior to informed consent, which they intend to use for at least 2 months after the last study vaccination.
Who cannot join
- Females of childbearing potential who are pregnant, lactating, or who have not adhered to a specified set of contraceptive methods from at least 30 days prior to study entry and who do not plan to do so until 2 months after the last study vaccination.
- A body mass index (BMI) ≥35 kg/m2.
- Progressive, unstable, or uncontrolled clinical conditions as per investigator's assessment. Subjects must be stable and unchanged for a minimum of 3 months.
- Hypersensitivity, including allergy, to any component of vaccines, medicinal products or medical equipment whose use is foreseen in this study.
- Clinical conditions representing a contraindication to intramuscular vaccination and blood draws.
- Abnormal function of the immune system resulting from:
Show all 17Show fewer
- Clinical conditions.
- Systemic administration of corticosteroids at a dose of ≥20 mg/day of prednisone or equivalent for more than 14 consecutive days within 90 days prior to informed consent. Topical, inhaled and intranasal corticosteroids are permitted. Intermittent use (one dose in 30 days) of intra-articular corticosteroids are also permitted.
- Administration of antineoplastic and immunomodulating agents or radiotherapy within 90 days prior to informed consent.
- History of any medical condition considered an adverse event of special interest (AESI).
- Received immunoglobulins with immunomodulating effects or any blood products within 180 days prior to informed consent.
- Received an investigational or non-registered medicinal product within 30 days prior to informed consent.
- Study personnel or immediate family or household member of study personnel.
- 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.
- Individuals who received any other vaccines (with the exception of COVID-19 vaccines) within 14 days (for inactivated vaccines) or 28 days (for live vaccines) prior to enrolment in this study or who are planning to receive any vaccine within 28 days from the study vaccines.
- Receipt of any (investigational or licensed) COVID-19 vaccine within 14 days (non-replicating vaccines) or 28 days (replicating vaccines) prior to enrollment or plan to receive any COVID-19 vaccine within 14 days from study vaccination.
- A known history of Guillain-Barre Syndrome or other demyelinating diseases such as encephalomyelitis and transverse myelitis.
Trial locations and contacts
7 sites in 2 countries.
7 sites in 2 countries
Philippines4 sites
West Visayas State University Medical Center
Iloilo City
Manila Doctors Hospital
Manila
Quirino Memorial Medical Center
Quezon City
Silang Specialists Medical Center
Silang
United States3 sites
Meridian Clinical Research
Lincoln, Nebraska, 68510
Meridian Clinical Research
Omaha, Nebraska, 58134
Meridian Clinical Research
Rockville, Maryland, 20854
About this study
Official title: A Phase 1, Randomized, Observer-Blind, Multi-Center, Dose Ranging Study to Evaluate the Immunogenicity, Safety and Tolerability of Different Formulations of an Adjuvanted or Non-Adjuvanted Cell Culture-derived A/H2N3 Subunit Influenza Virus Vaccine in Healthy Subjects 18 Years and Above
This Phase 1, randomized, observer-blind, dose-ranging clinical study is evaluating 6 different formulations of MF59-adjuvanted and non-adjuvanted H2N3 influenza vaccine. Approximately 600 healthy adult subjects are to be randomized into 1 of 6 possible treatment groups with 100 subjects per group, stratified by age group (born after or before 1968). Each subject will receive an influenza vaccine injection on Day 1 and Day 22. Subjects will be followed up for approximately 12 months after the second vaccine injection.
The primary immunogenicity analysis is based on the Day 1, Day 8, Day 22, Day 29, and Day 43 serology data. The primary safety analysis is based on solicited local and systemic adverse events (AEs) reported within 10 days after each vaccination, unsolicited AEs reported within 3 weeks after each vaccination, and serious AEs (SAEs), medically attended AEs (MAAEs), AEs leading to withdrawal from the study, and AEs of special interest (AESIs) reported throughout the study.
- Conditions
- Influenza, Human, Infections, Respiratory Tract Infections, Virus Diseases, Infection Viral
- Being tested
- Low dose A/H2N3c + standard dose MF59, Intermediate dose A/H2N3c + standard dose MF59, High dose A/H2N3c + standard dose MF59, High dose A/H2N3c non-adjuvanted, Lowest dose A/H2N3c + high dose MF59
- Keywords
- Influenza, Vaccine, MF59, Adjuvant, H2N3
- Medical subject headings
- Influenza, Human, Infections, Respiratory Tract Infections, Virus Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Low dose A/H2N3c + standard dose MF59Biological
Two intramuscular injections (3 weeks apart) of cell culture-derived MF59 adjuvanted H2N3 vaccine
Intermediate dose A/H2N3c + standard dose MF59Biological
Two intramuscular injections (3 weeks apart) of cell culture-derived MF59 adjuvanted H2N3 vaccine
High dose A/H2N3c + standard dose MF59Biological
Two intramuscular injections (3 weeks apart) of cell culture-derived MF59 adjuvanted H2N3 vaccine
High dose A/H2N3c non-adjuvantedBiological
Two intramuscular injections (3 weeks apart) of cell culture-derived non-adjuvanted H2N3 vaccine
Lowest dose A/H2N3c + high dose MF59Biological
Two intramuscular injections (3 weeks apart) of cell culture-derived MF59 adjuvanted H2N3 vaccine
Low dose A/H2N3c + high dose MF59Biological
Two intramuscular injections (3 weeks apart) of cell culture-derived MF59 adjuvanted H2N3 vaccine
| Study group | Role | What they receive |
|---|---|---|
| Group A | Experimental | Eligible subjects who have been randomized to receive two intramuscular vaccinations (3 weeks apart) of low dose A/H2N3c + standard dose MF59 adjuvant Receives: Biological: Low dose A/H2N3c + standard dose MF59 |
| Group B | Experimental | Eligible subjects who have been randomized to receive two intramuscular vaccinations (3 weeks apart) of intermediate dose A/H2N3c + standard dose MF59 adjuvant Receives: Biological: Intermediate dose A/H2N3c + standard dose MF59 |
| Group C | Experimental | Eligible subjects who have been randomized to receive two intramuscular vaccinations (3 weeks apart) of high dose A/H2N3c + standard dose MF59 adjuvant Receives: Biological: High dose A/H2N3c + standard dose MF59 |
| Group D | Experimental | Eligible subjects who have been randomized to receive two intramuscular vaccinations (3 weeks apart) of high dose A/H2N3c non-adjuvanted Receives: Biological: High dose A/H2N3c non-adjuvanted |
| Group E | Experimental | Eligible subjects who have been randomized to receive two intramuscular vaccinations (3 weeks apart) of lowest dose A/H2N3c + high dose MF59 adjuvant Receives: Biological: Lowest dose A/H2N3c + high dose MF59 |
| Group F | Experimental | Eligible subjects who have been randomized to receive two intramuscular vaccinations (3 weeks apart) of low dose A/H2N3c + high dose MF59 adjuvant Receives: Biological: Low dose A/H2N3c + high dose MF59 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Geometric mean titer (GMT) of hemagglutination inhibition (HI) antibodies against homologous H2N3 strain - Day 1
GMT (HI) prevaccination
Measured: Day 1
GMT of HI antibodies against homologous H2N3 strain - Day 8
GMT (HI) 1 week postvaccination 1
Measured: Day 8
GMT of HI antibodies against homologous H2N3 strain Day 22
GMT (HI) 3 weeks postvaccination 1
Measured: Day 22
GMT of HI antibodies against homologous H2N3 strain - Day 29
GMT (HI) 1 week postvaccination 2
Measured: Day 29
GMT of HI antibodies against homologous H2N3 strain - Day 43
GMT (HI) 3 weeks postvaccination 2
Measured: Day 43
GMT of microneutralization (MN) antibodies against homologous H2N3 strain - Day 1
GMT (MN) prevaccination
Measured: Day 1
GMT of MN antibodies against homologous H2N3 strain - Day 8
GMT (MN) 1 week postvaccination 1
Measured: Day 8
GMT of MN antibodies against homologous H2N3 strain - Day 22
GMT (MN) 3 weeks postvaccination 1
Measured: Day 22
GMT of MN antibodies against homologous H2N3 strain - Day 29
GMT (MN) 1 week postvaccination 2
Measured: Day 29
GMT of MN antibodies against homologous H2N3 strain - Day 43
GMT (MN) 3 weeks postvaccination 2
Measured: Day 43
Geometric mean fold increase (GMFI) of HI antibodies against homologous H2N3 strain - Day 8
GMFI (HI) 1 week postvaccination 1 compared to prevaccination
Measured: Day 8
GMFI of HI antibodies against homologous H2N3 strain - Day 22
GMFI (HI) 3 weeks postvaccination 1 compared to prevaccination
Measured: Day 22
GMFI of HI antibodies against homologous H2N3 strain - Day 29
GMFI (HI) 1 week postvaccination 2 compared to prevaccination
Measured: Day 29
GMFI of HI antibodies against homologous H2N3 strain - Day 43
GMFI (HI) 3 weeks postvaccination 2 compared to prevaccination
Measured: Day 43
GMFI of MN antibodies against homologous H2N3 strain - Day 8
GMFI (MN) 1 week postvaccination 1 compared to prevaccination
Measured: Day 8
GMFI of MN antibodies against homologous H2N3 strain - Day 22
GMFI (MN) 3 weeks postvaccination 1 compared to prevaccination
Measured: Day 22
GMFI of MN antibodies against homologous H2N3 strain - Day 29
GMFI (MN) 1 week postvaccination 2 compared to prevaccination
Measured: Day 29
GMFI of MN antibodies against homologous H2N3 strain - Day 43
GMFI (MN) 3 weeks postvaccination 2 compared to prevaccination
Measured: Day 43
Percentages of subjects with HI titers ≥1:40 against homologous H2N3 strain - Day 1
% ≥1:40 (HI) prevaccination
Measured: Day 1
Percentages of subjects with HI titers ≥1:40 against homologous H2N3 strain - Day 8
% ≥1:40 (HI) 1 week postvaccination 1
Measured: Day 8
Percentages of subjects with HI titers ≥1:40 against homologous H2N3 strain - Day 22
% ≥1:40 (HI) 3 weeks postvaccination 1
Measured: Day 22
Percentages of subjects with HI titers ≥1:40 against homologous H2N3 strain - Day 29
% ≥1:40 (HI) 1 week postvaccination 2
Measured: Day 29
Percentages of subjects with HI titers ≥1:40 against homologous H2N3 strain - Day 43
% ≥1:40 (HI) 3 weeks postvaccination 2
Measured: Day 43
Percentages of subjects with MN titers ≥1:40 against homologous H2N3 strain - Day 1
% ≥1:40 (MN) prevaccination
Measured: Day 1
Percentages of subjects with MN titers ≥1:40 against homologous H2N3 strain - Day 8
% ≥1:40 (MN) 1 week postvaccination 1
Measured: Day 8
Percentages of subjects with MN titers ≥1:40 against homologous H2N3 strain - Day 22
% ≥1:40 (MN) 3 weeks postvaccination 1
Measured: Day 22
Percentages of subjects with MN titers ≥1:40 against homologous H2N3 strain - Day 29
% ≥1:40 (MN) 1 week postvaccination 2
Measured: Day 29
Percentages of subjects with MN titers ≥1:40 against homologous H2N3 strain - Day 43
% ≥1:40 (MN) 3 weeks postvaccination 2
Measured: Day 43
Percentages of subjects with seroconversion by HI against homologous H2N3 strain - Day 8
% seroconversion (HI) 1 week postvaccination 1, defined as a ≥4-fold increase in HI titer postvaccination in those with prevaccination titer ≥1:10, or a postvaccination HI titer ≥1:40 for subjects with baseline titer <1:10
Measured: Day 8
Percentages of subjects with seroconversion by HI against homologous H2N3 strain - Day 22
% seroconversion (HI) 3 weeks postvaccination 1, defined as a ≥4-fold increase in HI titer postvaccination in those with prevaccination titer ≥1:10, or a postvaccination HI titer ≥1:40 for subjects with baseline titer <1:10
Measured: Day 22
Percentages of subjects with seroconversion by HI against homologous H2N3 strain - Day 29
% seroconversion (HI) 1 week postvaccination 2, defined as a ≥4-fold increase in HI titer postvaccination in those with prevaccination titer ≥1:10, or a postvaccination HI titer ≥1:40 for subjects with baseline titer <1:10
Measured: Day 29
Percentages of subjects with seroconversion by HI against homologous H2N3 strain - Day 43
% seroconversion (HI) 3 weeks postvaccination 2, defined as a ≥4-fold increase in HI titer postvaccination in those with prevaccination titer ≥1:10, or a postvaccination HI titer ≥1:40 for subjects with baseline titer <1:10
Measured: Day 43
Percentages of subjects with seroconversion by MN against homologous H2N3 strain - Day 8
% seroconversion (MN) 1 week postvaccination 1, defined as a ≥4-fold increase in MN titer postvaccination in those with prevaccination titer ≥lower limit of quantification (LLOQ), or a postvaccination MN titer ≥4×LLOQ for subjects with baseline titer <LLOQ
Measured: Day 8
Percentages of subjects with seroconversion by MN against homologous H2N3 strain - Day 22
% seroconversion (MN) 3 weeks postvaccination 1, defined as a ≥4-fold increase in MN titer postvaccination in those with prevaccination titer ≥lower limit of quantification (LLOQ), or a postvaccination MN titer ≥4×LLOQ for subjects with baseline titer <LLOQ
Measured: Day 22
Percentages of subjects with seroconversion by MN against homologous H2N3 strain - Day 29
% seroconversion (MN) 1 week postvaccination 2, defined as a ≥4-fold increase in MN titer postvaccination in those with prevaccination titer ≥lower limit of quantification (LLOQ), or a postvaccination MN titer ≥4×LLOQ for subjects with baseline titer <LLOQ
Measured: Day 29
Percentages of subjects with seroconversion by MN against homologous H2N3 strain - Day 43
% seroconversion (MN) 3 weeks postvaccination 2, defined as a ≥4-fold increase in MN titer postvaccination in those with prevaccination titer ≥lower limit of quantification (LLOQ), or a postvaccination MN titer ≥4×LLOQ for subjects with baseline titer <LLOQ
Measured: Day 43
Number and percentages of subjects reporting solicited local and systemic adverse events (AEs) - Day 1 through Day 10
10 consecutive days postvaccination 1
Measured: Day 1 through Day 10
Number and percentages of subjects reporting solicited local and systemic AEs - Day 22 through Day 31
10 consecutive days postvaccination 2
Measured: Day 22 through Day 31
Number and percentage of subjects reporting any unsolicited AEs
For 3 weeks following each vaccination
Measured: Day 1 through Day 43
Number and percentage of subjects reporting serious AEs (SAEs), AEs leading to withdrawal, AEs of special interest (AESI) and medically attended AEs (MAAEs)
From vaccination until study completion
Measured: Day 1 through Day 387
Secondary outcomes (14)
GMT of ELLA titers as a measure of anti-neuraminidase (NA) immunogenicity
GMT (ELLA) prevaccination, 1 and 3 weeks postvaccination
Measured: Day 1, Day 8, Day 22, Day 29, Day 43
GMFI of ELLA titers as a measure of anti-NA immunogenicity
GMFI (ELLA) 1 and 3 weeks postvaccination compared to prevaccination
Measured: Day 8, Day 22, Day 29, Day 43
Percentage of subjects with ≥4-fold increase in ELLA titer as a measure of anti-NA immunogenicity
% ≥4-fold increase (ELLA) 1 and 3 weeks postvaccination compared to prevaccination
Measured: Day 8, Day 22, Day 29, Day 43
GMT of HI antibodies against homologous H2N3 strain - Persistence
GMT (HI) 6 and 12 months postvaccination 2
Measured: Day 202, Day 387
GMT of MN antibodies against homologous H2N3 strain - Persistence
GMT (MN) 6 and 12 months postvaccination 2
Measured: Day 202, Day 387
GMT of ELLA titer as a measure of anti-NA immunogenicity- Persistence
GMT (ELLA) 6 and 12 months postvaccination 2
Measured: Day 202, Day 387
GMFI of HI antibodies against homologous H2N3 strain - Persistence
GMFI (HI) 6 and 12 months postvaccination 2 compared to prevaccination
Measured: Day 202, Day 387
GMFI of MN antibodies against homologous H2N3 strain - Persistence
GMFI (MN) 6 and 12 months postvaccination 2 compared to prevaccination
Measured: Day 202, Day 387
GMFI of ELLA titer as a measure of anti-NA immunogenicity- Persistence
GMFI (ELLA) 6 and 12 months postvaccination 2 compared to prevaccination
Measured: Day 202, Day 387
Percentages of subjects with HI titers ≥1:40 against homologous H2N3 strain - Persistence
% ≥1:40 (HI) 6 and 12 months postvaccination 2
Measured: Day 202, Day 387
Percentages of subjects with MN titers ≥1:40, ≥1:80 and ≥1:160 against homologous H2N3 strain - Persistence
% ≥1:40, ≥1:80 and ≥1:160 (MN) 6 and 12 months postvaccination 2
Measured: Day 202, Day 387
Percentages of subjects with seroconversion by HI against homologous H2N3 strain - Persistence
% seroconversion (HI) 6 and 12 months postvaccination 2, defined as a ≥4-fold increase in HI titer postvaccination in those with prevaccination titer ≥1:10, or a postvaccination HI titer ≥1:40 for subjects with baseline titer <1:10
Measured: Day 202, Day 387
Percentages of subjects with seroconversion by MN against homologous H2N3 strain - Persistence
% seroconversion (MN) 6 and 12 months postvaccination 2, defined as a ≥4-fold increase in MN titer postvaccination in those with prevaccination titer ≥LLOQ, or a postvaccination MN titer ≥4×LLOQ for subjects with baseline titer <LLOQ
Measured: Day 202, Day 387
Percentage of subjects with ≥4-fold increase in ELLA titer as a measure of anti-NA immunogenicity - Persistence
% ≥4-fold increase (ELLA) 6 and 12 months postvaccination 2 compared to prevaccination
Measured: Day 202, Day 387
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 May 2023
- Study start15 Jun 2023
- Primary completion15 Nov 2024
- Study completion15 Nov 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Influenza, HumanStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Eligible subjects are randomized in an equal ratio to one of the 6 different treatment groups (formulations) and will receive two doses of the allocated H2N3c vaccine (adjuvanted or non-adjuvanted) at 3 weeks apart, ie, at Day 1 and Day 22.
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 600 participants (actual)
Sponsor and investigators
- Lead sponsor
- Seqirus
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Biomedical Advanced Research and Development Authority
- Responsible party
- Sponsor
- Investigators
- Clinical Science and Strategy, Study chair, Seqirus
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05875961
- Sponsor's protocol ID
- V204_01
- Other IDs
- HHSO1002018000041
- Status last verified
- Jan 2025
- First submitted
- 5 May 2023
- Last updated
- 21 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 21 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 1, Randomized, Observer-Blind, Multi-Center, Dose Ranging Study to Evaluate the Immunogenicity, Safety and Tolerability of Different Formulations of an Adjuvanted or Non-Adjuvanted Cell Culture-derived A/H2N3 Subunit Influenza Virus Vaccine in Healthy Subjects 18 Years and Above
- ClinicalTrials.gov ID
- NCT05875961
- Acronym / sponsor ID
- V204_01
- Conditions
- Influenza, Human, Infections, Respiratory Tract Infections, Virus Diseases, Infection Viral
- Keywords
- Influenza, Vaccine, MF59, Adjuvant, H2N3
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 600 participants (actual)
- Lead sponsor
- SeqirusIndustry (pharma, biotech, devices)
- Collaborators
- Biomedical Advanced Research and Development Authority
- Study start
- 15 Jun 2023 (actual)
- Primary completion
- 15 Nov 2024 (actual)
- Study completion
- 15 Nov 2024 (actual)
- First posted
- 25 May 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This Phase 1, randomized, observer-blind, dose-ranging clinical study is evaluating 6 different formulations of MF59-adjuvanted and non-adjuvanted H2N3 influenza vaccine. Approximately 600 healthy adult subjects are to be randomized into 1 of 6 possible treatment groups with 100 subjects per group, stratified by age group (born after or before 1968). Each subject will receive an influenza vaccine injection on Day 1 and Day 22. Subjects will be followed up for approximately 12 months after the second vaccine injection.
The primary immunogenicity analysis is based on the Day 1, Day 8, Day 22, Day 29, and Day 43 serology data. The primary safety analysis is based on solicited local and systemic adverse events (AEs) reported within 10 days after each vaccination, unsolicited AEs reported within 3 weeks after each vaccination, and serious AEs (SAEs), medically attended AEs (MAAEs), AEs leading to withdrawal from the study, and AEs of special interest (AESIs) reported throughout the study.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 6
- Model description
- Eligible subjects are randomized in an equal ratio to one of the 6 different treatment groups (formulations) and will receive two doses of the allocated H2N3c vaccine (adjuvanted or non-adjuvanted) at 3 weeks apart, ie, at Day 1 and Day 22.
| Arm | Type | Receives |
|---|---|---|
| Group A | Experimental | Biological: Low dose A/H2N3c + standard dose MF59Eligible subjects who have been randomized to receive two intramuscular vaccinations (3 weeks apart) of low dose A/H2N3c + standard dose MF59 adjuvant |
| Group B | Experimental | Biological: Intermediate dose A/H2N3c + standard dose MF59Eligible subjects who have been randomized to receive two intramuscular vaccinations (3 weeks apart) of intermediate dose A/H2N3c + standard dose MF59 adjuvant |
| Group C | Experimental | Biological: High dose A/H2N3c + standard dose MF59Eligible subjects who have been randomized to receive two intramuscular vaccinations (3 weeks apart) of high dose A/H2N3c + standard dose MF59 adjuvant |
| Group D | Experimental | Biological: High dose A/H2N3c non-adjuvantedEligible subjects who have been randomized to receive two intramuscular vaccinations (3 weeks apart) of high dose A/H2N3c non-adjuvanted |
| Group E | Experimental | Biological: Lowest dose A/H2N3c + high dose MF59Eligible subjects who have been randomized to receive two intramuscular vaccinations (3 weeks apart) of lowest dose A/H2N3c + high dose MF59 adjuvant |
| Group F | Experimental | Biological: Low dose A/H2N3c + high dose MF59Eligible subjects who have been randomized to receive two intramuscular vaccinations (3 weeks apart) of low dose A/H2N3c + high dose MF59 adjuvant |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Individuals of 18 years of age and older on the day of informed consent who were not born in 1968.
- Individuals who have voluntarily given written informed consent after the nature of the study has been explained according to local regulatory requirements, prior to study entry.
- Individuals who can comply with study procedures including follow-up.
- Males, females of non-childbearing potential or females of childbearing potential who are using an effective birth control method, at least 30 days prior to informed consent, which they intend to use for at least 2 months after the last study vaccination.
Key exclusion criteria (17 listed)
- Females of childbearing potential who are pregnant, lactating, or who have not adhered to a specified set of contraceptive methods from at least 30 days prior to study entry and who do not plan to do so until 2 months after the last study vaccination.
- A body mass index (BMI) ≥35 kg/m2.
- Progressive, unstable, or uncontrolled clinical conditions as per investigator's assessment. Subjects must be stable and unchanged for a minimum of 3 months.
- Hypersensitivity, including allergy, to any component of vaccines, medicinal products or medical equipment whose use is foreseen in this study.
- Clinical conditions representing a contraindication to intramuscular vaccination and blood draws.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Low dose A/H2N3c + standard dose MF59Two intramuscular injections (3 weeks apart) of cell culture-derived MF59 adjuvanted H2N3 vaccine | Biological | Group A |
| Intermediate dose A/H2N3c + standard dose MF59Two intramuscular injections (3 weeks apart) of cell culture-derived MF59 adjuvanted H2N3 vaccine | Biological | Group B |
| High dose A/H2N3c + standard dose MF59Two intramuscular injections (3 weeks apart) of cell culture-derived MF59 adjuvanted H2N3 vaccine | Biological | Group C |
| High dose A/H2N3c non-adjuvantedTwo intramuscular injections (3 weeks apart) of cell culture-derived non-adjuvanted H2N3 vaccine | Biological | Group D |
| Lowest dose A/H2N3c + high dose MF59Two intramuscular injections (3 weeks apart) of cell culture-derived MF59 adjuvanted H2N3 vaccine | Biological | Group E |
| Low dose A/H2N3c + high dose MF59Two intramuscular injections (3 weeks apart) of cell culture-derived MF59 adjuvanted H2N3 vaccine | Biological | Group F |
Primary outcome
Geometric mean titer (GMT) of hemagglutination inhibition (HI) antibodies against homologous H2N3 strain - Day 1
Time frame: Day 1
GMT (HI) prevaccination
GMT of HI antibodies against homologous H2N3 strain - Day 8
Time frame: Day 8
GMT (HI) 1 week postvaccination 1
GMT of HI antibodies against homologous H2N3 strain Day 22
Time frame: Day 22
GMT (HI) 3 weeks postvaccination 1
GMT of HI antibodies against homologous H2N3 strain - Day 29
Time frame: Day 29
GMT (HI) 1 week postvaccination 2
GMT of HI antibodies against homologous H2N3 strain - Day 43
Time frame: Day 43
GMT (HI) 3 weeks postvaccination 2
GMT of microneutralization (MN) antibodies against homologous H2N3 strain - Day 1
Time frame: Day 1
GMT (MN) prevaccination
GMT of MN antibodies against homologous H2N3 strain - Day 8
Time frame: Day 8
GMT (MN) 1 week postvaccination 1
GMT of MN antibodies against homologous H2N3 strain - Day 22
Time frame: Day 22
GMT (MN) 3 weeks postvaccination 1
GMT of MN antibodies against homologous H2N3 strain - Day 29
Time frame: Day 29
GMT (MN) 1 week postvaccination 2
GMT of MN antibodies against homologous H2N3 strain - Day 43
Time frame: Day 43
GMT (MN) 3 weeks postvaccination 2
Geometric mean fold increase (GMFI) of HI antibodies against homologous H2N3 strain - Day 8
Time frame: Day 8
GMFI (HI) 1 week postvaccination 1 compared to prevaccination
GMFI of HI antibodies against homologous H2N3 strain - Day 22
Time frame: Day 22
GMFI (HI) 3 weeks postvaccination 1 compared to prevaccination
GMFI of HI antibodies against homologous H2N3 strain - Day 29
Time frame: Day 29
GMFI (HI) 1 week postvaccination 2 compared to prevaccination
GMFI of HI antibodies against homologous H2N3 strain - Day 43
Time frame: Day 43
GMFI (HI) 3 weeks postvaccination 2 compared to prevaccination
GMFI of MN antibodies against homologous H2N3 strain - Day 8
Time frame: Day 8
GMFI (MN) 1 week postvaccination 1 compared to prevaccination
GMFI of MN antibodies against homologous H2N3 strain - Day 22
Time frame: Day 22
GMFI (MN) 3 weeks postvaccination 1 compared to prevaccination
GMFI of MN antibodies against homologous H2N3 strain - Day 29
Time frame: Day 29
GMFI (MN) 1 week postvaccination 2 compared to prevaccination
GMFI of MN antibodies against homologous H2N3 strain - Day 43
Time frame: Day 43
GMFI (MN) 3 weeks postvaccination 2 compared to prevaccination
Percentages of subjects with HI titers ≥1:40 against homologous H2N3 strain - Day 1
Time frame: Day 1
% ≥1:40 (HI) prevaccination
Percentages of subjects with HI titers ≥1:40 against homologous H2N3 strain - Day 8
Time frame: Day 8
% ≥1:40 (HI) 1 week postvaccination 1
Percentages of subjects with HI titers ≥1:40 against homologous H2N3 strain - Day 22
Time frame: Day 22
% ≥1:40 (HI) 3 weeks postvaccination 1
Percentages of subjects with HI titers ≥1:40 against homologous H2N3 strain - Day 29
Time frame: Day 29
% ≥1:40 (HI) 1 week postvaccination 2
Percentages of subjects with HI titers ≥1:40 against homologous H2N3 strain - Day 43
Time frame: Day 43
% ≥1:40 (HI) 3 weeks postvaccination 2
Percentages of subjects with MN titers ≥1:40 against homologous H2N3 strain - Day 1
Time frame: Day 1
% ≥1:40 (MN) prevaccination
Percentages of subjects with MN titers ≥1:40 against homologous H2N3 strain - Day 8
Time frame: Day 8
% ≥1:40 (MN) 1 week postvaccination 1
Percentages of subjects with MN titers ≥1:40 against homologous H2N3 strain - Day 22
Time frame: Day 22
% ≥1:40 (MN) 3 weeks postvaccination 1
Percentages of subjects with MN titers ≥1:40 against homologous H2N3 strain - Day 29
Time frame: Day 29
% ≥1:40 (MN) 1 week postvaccination 2
Percentages of subjects with MN titers ≥1:40 against homologous H2N3 strain - Day 43
Time frame: Day 43
% ≥1:40 (MN) 3 weeks postvaccination 2
Percentages of subjects with seroconversion by HI against homologous H2N3 strain - Day 8
Time frame: Day 8
% seroconversion (HI) 1 week postvaccination 1, defined as a ≥4-fold increase in HI titer postvaccination in those with prevaccination titer ≥1:10, or a postvaccination HI titer ≥1:40 for subjects with baseline titer <1:10
Percentages of subjects with seroconversion by HI against homologous H2N3 strain - Day 22
Time frame: Day 22
% seroconversion (HI) 3 weeks postvaccination 1, defined as a ≥4-fold increase in HI titer postvaccination in those with prevaccination titer ≥1:10, or a postvaccination HI titer ≥1:40 for subjects with baseline titer <1:10
Percentages of subjects with seroconversion by HI against homologous H2N3 strain - Day 29
Time frame: Day 29
% seroconversion (HI) 1 week postvaccination 2, defined as a ≥4-fold increase in HI titer postvaccination in those with prevaccination titer ≥1:10, or a postvaccination HI titer ≥1:40 for subjects with baseline titer <1:10
Percentages of subjects with seroconversion by HI against homologous H2N3 strain - Day 43
Time frame: Day 43
% seroconversion (HI) 3 weeks postvaccination 2, defined as a ≥4-fold increase in HI titer postvaccination in those with prevaccination titer ≥1:10, or a postvaccination HI titer ≥1:40 for subjects with baseline titer <1:10
Percentages of subjects with seroconversion by MN against homologous H2N3 strain - Day 8
Time frame: Day 8
% seroconversion (MN) 1 week postvaccination 1, defined as a ≥4-fold increase in MN titer postvaccination in those with prevaccination titer ≥lower limit of quantification (LLOQ), or a postvaccination MN titer ≥4×LLOQ for subjects with baseline titer <LLOQ
Percentages of subjects with seroconversion by MN against homologous H2N3 strain - Day 22
Time frame: Day 22
% seroconversion (MN) 3 weeks postvaccination 1, defined as a ≥4-fold increase in MN titer postvaccination in those with prevaccination titer ≥lower limit of quantification (LLOQ), or a postvaccination MN titer ≥4×LLOQ for subjects with baseline titer <LLOQ
Percentages of subjects with seroconversion by MN against homologous H2N3 strain - Day 29
Time frame: Day 29
% seroconversion (MN) 1 week postvaccination 2, defined as a ≥4-fold increase in MN titer postvaccination in those with prevaccination titer ≥lower limit of quantification (LLOQ), or a postvaccination MN titer ≥4×LLOQ for subjects with baseline titer <LLOQ
Percentages of subjects with seroconversion by MN against homologous H2N3 strain - Day 43
Time frame: Day 43
% seroconversion (MN) 3 weeks postvaccination 2, defined as a ≥4-fold increase in MN titer postvaccination in those with prevaccination titer ≥lower limit of quantification (LLOQ), or a postvaccination MN titer ≥4×LLOQ for subjects with baseline titer <LLOQ
Number and percentages of subjects reporting solicited local and systemic adverse events (AEs) - Day 1 through Day 10
Time frame: Day 1 through Day 10
10 consecutive days postvaccination 1
Number and percentages of subjects reporting solicited local and systemic AEs - Day 22 through Day 31
Time frame: Day 22 through Day 31
10 consecutive days postvaccination 2
Number and percentage of subjects reporting any unsolicited AEs
Time frame: Day 1 through Day 43
For 3 weeks following each vaccination
Number and percentage of subjects reporting serious AEs (SAEs), AEs leading to withdrawal, AEs of special interest (AESI) and medically attended AEs (MAAEs)
Time frame: Day 1 through Day 387
From vaccination until study completion
14 secondary outcomes
GMT of ELLA titers as a measure of anti-neuraminidase (NA) immunogenicity
Time frame: Day 1, Day 8, Day 22, Day 29, Day 43
GMFI of ELLA titers as a measure of anti-NA immunogenicity
Time frame: Day 8, Day 22, Day 29, Day 43
Percentage of subjects with ≥4-fold increase in ELLA titer as a measure of anti-NA immunogenicity
Time frame: Day 8, Day 22, Day 29, Day 43
GMT of HI antibodies against homologous H2N3 strain - Persistence
Time frame: Day 202, Day 387
GMT of MN antibodies against homologous H2N3 strain - Persistence
Time frame: Day 202, Day 387
GMT of ELLA titer as a measure of anti-NA immunogenicity- Persistence
Time frame: Day 202, Day 387
GMFI of HI antibodies against homologous H2N3 strain - Persistence
Time frame: Day 202, Day 387
GMFI of MN antibodies against homologous H2N3 strain - Persistence
Time frame: Day 202, Day 387
GMFI of ELLA titer as a measure of anti-NA immunogenicity- Persistence
Time frame: Day 202, Day 387
Percentages of subjects with HI titers ≥1:40 against homologous H2N3 strain - Persistence
Time frame: Day 202, Day 387
Percentages of subjects with MN titers ≥1:40, ≥1:80 and ≥1:160 against homologous H2N3 strain - Persistence
Time frame: Day 202, Day 387
Percentages of subjects with seroconversion by HI against homologous H2N3 strain - Persistence
Time frame: Day 202, Day 387
Percentages of subjects with seroconversion by MN against homologous H2N3 strain - Persistence
Time frame: Day 202, Day 387
Percentage of subjects with ≥4-fold increase in ELLA titer as a measure of anti-NA immunogenicity - Persistence
Time frame: Day 202, Day 387
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Sep 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Clinical Science and Strategy study chair
Seqirus
7 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Low dose A/H2N3c + standard dose MF59, Intermediate dose A/H2N3c + standard dose MF59 and High dose A/H2N3c + standard dose MF59 in people with Influenza, Human and Infections, run by Seqirus at 7 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 17 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 21 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 7 sites in Philippines, United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Geometric mean titer (GMT) of hemagglutination inhibition (HI) antibodies against homologous H2N3 strain - Day 1 (time frame: Day 1). The study lists 40 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Sep 2026.