Influenza (Healthy Volunteers)Phase 3NCT05144945

Study Describing the Immunogenicity and Safety of Quadrivalent Recombinant Influenza Vaccine (RIV4) Versus a Licensed Quadrivalent-inactivated Influenza Vaccine (IIV4) (Fluarix® Quadrivalent) in Participants 18 Years of Age and Older in South Korea

A Phase 3 study testing Quadrivalent Recombinant Influenza Vaccine (RIV4) and Quadrivalent inactivated influenza vaccine (IIV4) in people with Influenza (Healthy Volunteers), run by Sanofi Pasteur, a Sanofi Company at 3 sites in South Korea.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

Search all trials

Trial summary

To describe the immune response induced by quadrivalent recombinant influenza vaccine (RIV4) and Quadrivalent-inactivated Influenza Vaccine (IIV4) in 18-49 and greater than or equal to (>=) 50 years of age participants by hemagglutination inhibition (HAI) measurement method. Read more about this study

Who is it for?: Ages 18 years and olderHealthy volunteers can take part
Conditions the study is for: Influenza (Healthy Volunteers)
What is being tested?: Quadrivalent Recombinant Influenza Vaccine (RIV4) and Quadrivalent inactivated influenza vaccine (IIV4)
Type of treatment: Vaccines, Injection or infusion
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 301 participants
Where: 3 sitesSouth Korea
Study dates: 7 Dec 2021to 1 Sep 2022
Phase: Phase 3
Are there results?: Yes, posted in the registrySummary in the doctors' view

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

Aged >=18 years on the day of inclusion.
Participants who were overtly healthy as determined by medical evaluation including medical history, physical examination.
Able to attend all scheduled visits and complied with all study procedures.
Informed consent form was signed and dated.
A female participant was eligible to participate if she was not pregnant or breastfeeding and one of the following conditions applies:
Was of non-childbearing potential. To be considered of non-childbearing potential, a female must be postmenopausal for at least 1 year, or surgically sterile OR Was of childbearing potential and agreed to use an effective contraceptive method or abstinence from at least 4 weeks prior to the study intervention administration until at least 4 weeks after study intervention administration.
A female participant of childbearing potential must had a negative highly sensitive pregnancy test (urine) before the first dose of study intervention.

Who cannot join

Participants were excluded from the study if any of the following criteria applied:
Participation at the time of study enrollment, or in the 6 months preceding the study vaccination, or planned participation during the present study period in another clinical study investigating involving an Investigational Medical Product (IMP) (vaccine, drug), medical device, or medical procedure or in any other type of medical research.
Receipt of any vaccine in the 4 weeks (28 days) preceding the study vaccination or planned receipt of any vaccine prior to Visit 2.
Previous vaccination against influenza (in the preceding 6 months) with either the study vaccine or another vaccine.
Receipt of immune globulins, blood, or blood-derived products in the past 3 months.
Known or suspected abnormal immune function: immunosuppression, suspected congenital or acquired immunodeficiency based on medical history and physical examination, or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy, or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months).

Show all 16Show fewer

Known systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to the vaccines used in the study or to a vaccine containing any of the same substances.
Thrombocytopenia or bleeding disorder, contraindicating IM vaccination based on the Investigator's judgment.
Deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalized involuntarily.
Current alcohol abuse or drug addiction that in the opinion of the Investigator might interfere with the study conduct or completion.
Chronic illness that, in the opinion of the Investigator, was at a stage where it might interfere with trial conduct or completion (Chronic illness may include, but is not limited to, cardiac disorders, renal disorders, auto-immune disorders, diabetes, psychiatric disorders, or chronic infection).
Moderate or severe acute illness/infection (according to Investigator judgment) on the day of vaccination or febrile illness (temperature >=38.0°C). A prospective participant should not be included in the study until the condition had resolved or the febrile event had subsided.
Personal or family history of Guillain-Barré syndrome.
Neoplastic disease or any hematologic malignancy (except localized skin or prostate cancer that was stable at the time of vaccination in the absence of therapy and participants who had a history of neoplastic disease and had been disease-free for >= 5 years).
Identified as an Investigator or employee of the Investigator or study center with direct involvement in the proposed study, or identified as an immediate family member (i.e., parent, spouse) of the Investigator or employee with direct involvement in the proposed study.
The above information was not intended to contain all considerations relevant to a potential participation in a clinical trial.

Trial locations and contacts

3 sites in 1 country.

South Korea3 sites

Investigational Site Number :4100003
Ansan-si, Gyeonggi-do, 15355
Investigational Site Number :4100001
Seoul, Seoul-teukbyeolsi, 152-703
Investigational Site Number :4100002
Seoul, 07441

Other trials in South Korea

About this study

Official title: A Phase III Randomized, Modified Double-blind, Active-controlled, Multi-center Study to Describe the Immunogenicity and Safety of the Quadrivalent Recombinant Influenza Vaccine (RIV4) Versus a Quadrivalent-inactivated Influenza Vaccine (IIV4) (Fluarix® Quadrivalent) in Participants 18 Years of Age and Older in South Korea

To describe the immune response induced by quadrivalent recombinant influenza vaccine (RIV4) and Quadrivalent-inactivated Influenza Vaccine (IIV4) in 18-49 and greater than or equal to (>=) 50 years of age participants by hemagglutination inhibition (HAI) measurement method.
To describe the safety profile of all participants in RIV4 and IIV4 groups.

Read the detailed description

The duration of each participant's participation was approximately 6 months.

Conditions: Influenza (Healthy Volunteers)
Being tested: Quadrivalent Recombinant Influenza Vaccine (RIV4), Quadrivalent inactivated influenza vaccine (IIV4)
Medical subject headings: Influenza, Human

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Quadrivalent Recombinant Influenza Vaccine (RIV4)Biological
Solution for intramuscular injection
Quadrivalent inactivated influenza vaccine (IIV4)Biological
Also called Fluarix®
Suspension for intramuscular injection

Study groups in NCT05144945
Study group	Role	What they receive
Group 1: Quadrivalent Recombinant Influenza Vaccine (RIV4)	Experimental	Participants received a single intramuscular (IM) injection of 0.5 milliliters (mL) RIV4 on Day 1. Receives: Biological: Quadrivalent Recombinant Influenza Vaccine (RIV4)
Group 2: Quadrivalent-inactivated Influenza Vaccine (IIV4)	Active comparator	Participants received a single IM injection of 0.5 mL IIV4 on Day 1. Receives: Biological: Quadrivalent inactivated influenza vaccine (IIV4)

What is being measured

The primary outcome is the main question the study is designed to answer.

Geometric Mean Titers (GMTs) of Influenza Vaccine Antibodies at Day 1- Per Protocol Analysis Set (PPAS)
GMTs of anti-influenza antibodies were measured using hemagglutination inhibition (HAI) assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Titers were expressed in terms of 1/dilution.
Measured: Day 1 (pre-vaccination)
Geometric Mean Titers (GMTs) of Influenza Vaccine Antibodies at Day 1- Full Analysis Set (FAS)
GMTs of anti-influenza antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Titers were expressed in terms of 1/dilution.
Measured: Day 1 (pre-vaccination)
Geometric Mean Titers (GMTs) of Influenza Vaccine Antibodies at Day 29- PPAS
GMTs of anti-influenza antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Titers were expressed in terms of 1/dilution.
Measured: Day 29 (post-vaccination)
Geometric Mean Titers (GMTs) of Influenza Vaccine Antibodies at Day 29- FAS
GMTs of anti-influenza antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Titers were expressed in terms of 1/dilution.
Measured: Day 29 (post-vaccination)
Geometric Mean Fold-rise (GMFR) for Influenza Vaccine Antibodies-PPAS
GMTs of anti-influenza antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. GMFR were calculated as the ratio of GMTs post-vaccination (on Day 29) and pre-vaccination (on Day 1).
Measured: Day 1 (pre-vaccination) and Day 29 (post-vaccination)
Geometric Mean Fold-rise (GMFR) for Influenza Vaccine Antibodies-FAS
GMTs of anti-influenza antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. GMFR were calculated as the ratio of GMTs post-vaccination (on Day 29) and pre-vaccination (on Day 1).
Measured: Day 1 (pre-vaccination) and Day 29 (post-vaccination)
Percentage of Participants Achieving Seroconversion Against Influenza Vaccine Antibodies-PPAS
Anti-influenza antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Seroconversion was defined as either a pre-vaccination titer less than (<) 1:10 (1/dilution) and a post-vaccination titer >=1:40 (1/dilution) or a pre-vaccination titer >= 1:10 (1/dilution) and a >= four-fold increase in post-vaccination titer at Day 29.
Measured: Day 29 (post-vaccination)
Percentage of Participants Achieving Seroconversion Against Influenza Vaccine Antibodies-FAS
Anti-influenza antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Seroconversion was defined as either a pre-vaccination titer less than (<) 1:10 (1/dilution) and a post-vaccination titer >=1:40 (1/dilution) or a pre-vaccination titer >= 1:10 (1/dilution) and a >= four-fold increase in post-vaccination titer at Day 29.
Measured: Day 29 (post-vaccination)
Percentage of Participants With Antibody Titers Greater Than or Equal to (>=) 40 (1/Dilution) Against Influenza Vaccine Antibodies-PPAS
Antibody titers were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Percentage of participants with antibody titers >=40 (1/dilution) against influenza vaccine antibodies at Day 1 and Day 29 were reported in this outcome measure.
Measured: Day 1 (pre-vaccination) and Day 29 (post-vaccination)
Percentage of Participants With Antibody Titers >=40 (1/Dilution) Against Influenza Vaccine Antibodies-FAS
Antibody titers were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Percentage of participants with antibody titers >=40 (1/dilution) against influenza vaccine antibodies at Day 1 and Day 29 were reported in this outcome measure.
Measured: Day 1 (pre-vaccination) and Day 29 (post-vaccination)
Percentage of Participants With Detectable Antibody Titers >= 10 (1/Dilution) Against Influenza Vaccine Antibodies- PPAS
Antibody titers were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Percentage of participants with antibody titers >=10 (1/dilution) against influenza vaccine antibodies at Day 1 and Day 29 were reported in this outcome measure.
Measured: Day 1 (pre-vaccination) and Day 29 (post-vaccination)
Percentage of Participants With Detectable Antibody Titers >= 10 (1/Dilution) Against Influenza Vaccine Antibodies- FAS
Antibody titers were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Percentage of participants with antibody titers >=10 (1/dilution) against influenza vaccine antibodies at Day 1 and Day 29 were reported in this outcome measure.
Measured: Day 1 (pre-vaccination) and Day 29 (post-vaccination)
Number of Participants Reporting Immediate Unsolicited Adverse Events (AEs)
An AE was any untoward medical occurrence in a clinical investigation participant administered a medicinal product and which did not had any casual relationship with the treatment. An unsolicited AE was an observed AE that did not fulfill the conditions prelisted in the case report form (CRF) in terms of diagnosis and/or onset window post-vaccination. All participants were observed for 30 minutes after vaccination, and any unsolicited AEs occurred during that time were recorded as immediate unsolicited AEs in the CRF.
Measured: Within 30 minutes post-vaccination
Number of Participants Reporting Solicited Systemic Reactions
A solicited reaction was an expected adverse reaction (sign or symptom) observed and reported under the conditions (nature and onset) prelisted (i.e., solicited) in the CRF and considered as related to the study intervention administered. Solicited systemic reactions included fever, headache, malaise, myalgia, shivering, fatigue, nausea, and arthralgia.
Measured: Within 7 days post-vaccination
Number of Participants Reporting Solicited Injection Site Reactions
A solicited reaction was an expected adverse reaction (sign or symptom) observed and reported under the conditions (nature and onset) prelisted (i.e., solicited) in the CRF and considered as related to the study intervention administered. Solicited injection site reactions included pain, erythema, swelling, induration, bruising and tenderness.
Measured: Within 7 days post-vaccination
Number of Participants Reporting Unsolicited Adverse Events (AEs)
An AE was any untoward medical occurrence in a clinical investigation participant administered a medicinal product and which did not had any casual relationship with the treatment. An unsolicited AE was an observed AE that did not fulfill the conditions prelisted in the CRF in terms of diagnosis and/or onset window post-vaccination.
Measured: From Day 1 up to 28 days post-vaccination (i.e., up to Day 29)
Number of Participants Reporting Serious Adverse Events (SAEs) And Adverse Events of Special Interest (AESI)
A SAE was any untoward medical occurrence that at any dose resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, or was an important medical event. A SAE which caused death of the participant was considered as fatal SAE. An AESIs were defined as one of scientific and medical concern specific to the Sponsor's study intervention, events for which ongoing monitoring and rapid communication by the investigator to the sponsor was done.
Measured: From Day 1 up to 6 months post-vaccination (i.e., up to Day 181)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

7 Dec 20211 Sep 2022

First posted6 Dec 2021
Study start7 Dec 2021
Primary completion1 Sep 2022
Study completion1 Sep 2022

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Publications (1)Papers the sponsor has linked to this study.
Other trials for Influenza (Healthy Volunteers)Studies of the same condition, open and under way.
More trials run by Sanofi Pasteur, a Sanofi CompanyThe sponsor's other registered studies.
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 3
Primary purpose: Prevention
Allocation: Randomised
Intervention model: Parallel groups
Model description: In each age group (18-49 and \>= 50 years of age), participants were randomized in a 1:1 ratio to each of the vaccines.
Masking: Quadruple blind
Who is masked: Participant, Care provider, Investigator, Outcomes assessor
Enrolment: 301 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT05144945
Sponsor's protocol ID: VAP00016
Other IDs: U1111-1253-2122
Status last verified: Sep 2025
First submitted: 17 Nov 2021
Last updated: 11 Sep 2025
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: Yes
FDA-regulated device: No
Individual data sharing: Yes: Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org

Publications

Choi WS, Lee J, Ottaviano C, Samson S, Peng L, Shin S, Choe S, Kim WJ. Immunogenicity and safety of quadrivalent recombinant influenza vaccine in Korean adults: Phase III, randomized study. Vaccine. 2025 Aug 30;62:127521. doi: 10.1016/j.vaccine.2025.127521. Epub 2025 Aug 5.
PubMed 40752250

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

RecruitingObservational study
Screening for LID Clinical Studies Unit Healthy Volunteer Protocols
Zika, Influenza
RecruitingPhase 1
A Trial to Evaluate the Effect of CD388/MK1406 on the Immunogenicity of Fluzone® HD Vaccine (CD388.SQ.1.08/MK-1406-007)
Healthy Participants
Active, not recruitingPhase 3
A Clinical Study to Evaluate the Safety, Tolerability, and Immunogenicity of VAX-31 With Influenza Vaccine in Adults ≥ 50 Years of Age
Pneumococcal Disease
Not yet recruitingPhase 3
Study of a Combination SARS-CoV-2 Recombinant Spike and High-Dose Inactivated Influenza Vaccine With Matrix-M Adjuvant in Adult Participants 60 Years of Age and Older
Immunization, Healthy Volunteers
RecruitingObservational study
Post-marketing Surveillance Study for the Safety of Efluelda® Pre-filled Syringe
Influenza Immunization, Healthy Volunteers

All Influenza (Healthy Volunteers) trials

Study at a glance

From the registry record, last updated by the sponsor on 11 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Phase III Randomized, Modified Double-blind, Active-controlled, Multi-center Study to Describe the Immunogenicity and Safety of the Quadrivalent Recombinant Influenza Vaccine (RIV4) Versus a Quadrivalent-inactivated Influenza Vaccine (IIV4) (Fluarix® Quadrivalent) in Participants 18 Years of Age and Older in South Korea
ClinicalTrials.gov ID: NCT05144945
Acronym / sponsor ID: VAP00016
Conditions: Influenza (Healthy Volunteers)
Phase: Phase 3
Study type: Interventional
Recruitment status: Completed
Enrolment: 301 participants (actual)
Lead sponsor: Sanofi Pasteur, a Sanofi CompanyIndustry (pharma, biotech, devices)
Study start: 7 Dec 2021 (actual)
Primary completion: 1 Sep 2022 (actual)
Study completion: 1 Sep 2022 (actual)
First posted: 6 Dec 2021 (actual)
Results: Posted 29 Sep 2023

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

To describe the immune response induced by quadrivalent recombinant influenza vaccine (RIV4) and Quadrivalent-inactivated Influenza Vaccine (IIV4) in 18-49 and greater than or equal to (>=) 50 years of age participants by hemagglutination inhibition (HAI) measurement method.
To describe the safety profile of all participants in RIV4 and IIV4 groups.

Detailed description

The duration of each participant's participation was approximately 6 months.

Study design

Primary purpose: Prevention
Allocation: Randomised
Intervention model: Parallel groups
Masking: Quadruple blind (participant, care provider, investigator, outcomes assessor)
Number of arms: 2
Model description: In each age group (18-49 and >= 50 years of age), participants were randomized in a 1:1 ratio to each of the vaccines.

Arm	Type	Receives
Group 1: Quadrivalent Recombinant Influenza Vaccine (RIV4)	Experimental	Biological: Quadrivalent Recombinant Influenza Vaccine (RIV4)Participants received a single intramuscular (IM) injection of 0.5 milliliters (mL) RIV4 on Day 1.
Group 2: Quadrivalent-inactivated Influenza Vaccine (IIV4)	Active comparator	Biological: Quadrivalent inactivated influenza vaccine (IIV4)Participants received a single IM injection of 0.5 mL IIV4 on Day 1.

Who may qualify

Ages: 18 years and older
Sex: All
Healthy volunteers: Accepted
Age groups: Adult, Older adult

Key inclusion criteria (7 listed)

Aged >=18 years on the day of inclusion.
Participants who were overtly healthy as determined by medical evaluation including medical history, physical examination.
Able to attend all scheduled visits and complied with all study procedures.
Informed consent form was signed and dated.
A female participant was eligible to participate if she was not pregnant or breastfeeding and one of the following conditions applies:

Key exclusion criteria (16 listed)

Participation at the time of study enrollment, or in the 6 months preceding the study vaccination, or planned participation during the present study period in another clinical study investigating involving an Investigational Medical Product (IMP) (vaccine, drug), medical device, or medical procedure or in any other type of medical research.
Receipt of any vaccine in the 4 weeks (28 days) preceding the study vaccination or planned receipt of any vaccine prior to Visit 2.
Previous vaccination against influenza (in the preceding 6 months) with either the study vaccine or another vaccine.
Receipt of immune globulins, blood, or blood-derived products in the past 3 months.
Known or suspected abnormal immune function: immunosuppression, suspected congenital or acquired immunodeficiency based on medical history and physical examination, or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy, or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months).

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
Quadrivalent Recombinant Influenza Vaccine (RIV4)Solution for intramuscular injection	Biological	Group 1: Quadrivalent Recombinant Influenza Vaccine (RIV4)
Quadrivalent inactivated influenza vaccine (IIV4)Also: Fluarix®Suspension for intramuscular injection	Biological	Group 2: Quadrivalent-inactivated Influenza Vaccine (IIV4)

Primary outcome

Geometric Mean Titers (GMTs) of Influenza Vaccine Antibodies at Day 1- Per Protocol Analysis Set (PPAS)
Time frame: Day 1 (pre-vaccination)
GMTs of anti-influenza antibodies were measured using hemagglutination inhibition (HAI) assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Titers were expressed in terms of 1/dilution.
Geometric Mean Titers (GMTs) of Influenza Vaccine Antibodies at Day 1- Full Analysis Set (FAS)
Time frame: Day 1 (pre-vaccination)
GMTs of anti-influenza antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Titers were expressed in terms of 1/dilution.
Geometric Mean Titers (GMTs) of Influenza Vaccine Antibodies at Day 29- PPAS
Time frame: Day 29 (post-vaccination)
GMTs of anti-influenza antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Titers were expressed in terms of 1/dilution.
Geometric Mean Titers (GMTs) of Influenza Vaccine Antibodies at Day 29- FAS
Time frame: Day 29 (post-vaccination)
GMTs of anti-influenza antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Titers were expressed in terms of 1/dilution.
Geometric Mean Fold-rise (GMFR) for Influenza Vaccine Antibodies-PPAS
Time frame: Day 1 (pre-vaccination) and Day 29 (post-vaccination)
GMTs of anti-influenza antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. GMFR were calculated as the ratio of GMTs post-vaccination (on Day 29) and pre-vaccination (on Day 1).
Geometric Mean Fold-rise (GMFR) for Influenza Vaccine Antibodies-FAS
Time frame: Day 1 (pre-vaccination) and Day 29 (post-vaccination)
GMTs of anti-influenza antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. GMFR were calculated as the ratio of GMTs post-vaccination (on Day 29) and pre-vaccination (on Day 1).
Percentage of Participants Achieving Seroconversion Against Influenza Vaccine Antibodies-PPAS
Time frame: Day 29 (post-vaccination)
Anti-influenza antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Seroconversion was defined as either a pre-vaccination titer less than (<) 1:10 (1/dilution) and a post-vaccination titer >=1:40 (1/dilution) or a pre-vaccination titer >= 1:10 (1/dilution) and a >= four-fold increase in post-vaccination titer at Day 29.
Percentage of Participants Achieving Seroconversion Against Influenza Vaccine Antibodies-FAS
Time frame: Day 29 (post-vaccination)
Anti-influenza antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Seroconversion was defined as either a pre-vaccination titer less than (<) 1:10 (1/dilution) and a post-vaccination titer >=1:40 (1/dilution) or a pre-vaccination titer >= 1:10 (1/dilution) and a >= four-fold increase in post-vaccination titer at Day 29.
Percentage of Participants With Antibody Titers Greater Than or Equal to (>=) 40 (1/Dilution) Against Influenza Vaccine Antibodies-PPAS
Time frame: Day 1 (pre-vaccination) and Day 29 (post-vaccination)
Antibody titers were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Percentage of participants with antibody titers >=40 (1/dilution) against influenza vaccine antibodies at Day 1 and Day 29 were reported in this outcome measure.
Percentage of Participants With Antibody Titers >=40 (1/Dilution) Against Influenza Vaccine Antibodies-FAS
Time frame: Day 1 (pre-vaccination) and Day 29 (post-vaccination)
Antibody titers were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Percentage of participants with antibody titers >=40 (1/dilution) against influenza vaccine antibodies at Day 1 and Day 29 were reported in this outcome measure.
Percentage of Participants With Detectable Antibody Titers >= 10 (1/Dilution) Against Influenza Vaccine Antibodies- PPAS
Time frame: Day 1 (pre-vaccination) and Day 29 (post-vaccination)
Antibody titers were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Percentage of participants with antibody titers >=10 (1/dilution) against influenza vaccine antibodies at Day 1 and Day 29 were reported in this outcome measure.
Percentage of Participants With Detectable Antibody Titers >= 10 (1/Dilution) Against Influenza Vaccine Antibodies- FAS
Time frame: Day 1 (pre-vaccination) and Day 29 (post-vaccination)
Antibody titers were measured using HAI assay for 4 influenza virus strains: A/H1N1, A/H3N2, B/Victoria, and B/Yamagata lineages. Percentage of participants with antibody titers >=10 (1/dilution) against influenza vaccine antibodies at Day 1 and Day 29 were reported in this outcome measure.
Number of Participants Reporting Immediate Unsolicited Adverse Events (AEs)
Time frame: Within 30 minutes post-vaccination
An AE was any untoward medical occurrence in a clinical investigation participant administered a medicinal product and which did not had any casual relationship with the treatment. An unsolicited AE was an observed AE that did not fulfill the conditions prelisted in the case report form (CRF) in terms of diagnosis and/or onset window post-vaccination. All participants were observed for 30 minutes after vaccination, and any unsolicited AEs occurred during that time were recorded as immediate unsolicited AEs in the CRF.
Number of Participants Reporting Solicited Systemic Reactions
Time frame: Within 7 days post-vaccination
A solicited reaction was an expected adverse reaction (sign or symptom) observed and reported under the conditions (nature and onset) prelisted (i.e., solicited) in the CRF and considered as related to the study intervention administered. Solicited systemic reactions included fever, headache, malaise, myalgia, shivering, fatigue, nausea, and arthralgia.
Number of Participants Reporting Solicited Injection Site Reactions
Time frame: Within 7 days post-vaccination
A solicited reaction was an expected adverse reaction (sign or symptom) observed and reported under the conditions (nature and onset) prelisted (i.e., solicited) in the CRF and considered as related to the study intervention administered. Solicited injection site reactions included pain, erythema, swelling, induration, bruising and tenderness.
Number of Participants Reporting Unsolicited Adverse Events (AEs)
Time frame: From Day 1 up to 28 days post-vaccination (i.e., up to Day 29)
An AE was any untoward medical occurrence in a clinical investigation participant administered a medicinal product and which did not had any casual relationship with the treatment. An unsolicited AE was an observed AE that did not fulfill the conditions prelisted in the CRF in terms of diagnosis and/or onset window post-vaccination.
Number of Participants Reporting Serious Adverse Events (SAEs) And Adverse Events of Special Interest (AESI)
Time frame: From Day 1 up to 6 months post-vaccination (i.e., up to Day 181)
A SAE was any untoward medical occurrence that at any dose resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, or was an important medical event. A SAE which caused death of the participant was considered as fatal SAE. An AESIs were defined as one of scientific and medical concern specific to the Sponsor's study intervention, events for which ongoing monitoring and rapid communication by the investigator to the sponsor was done.

Results and safety

Results posted to the registry on 29 Sep 2023, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Group 1: Quadrivalent Recombinant Influenza Vaccine (RIV4)	150	149
Group 2: Quadrivalent-inactivated Influenza Vaccine (IIV4)	151	151

Primary outcome: Geometric Mean Titers (GMTs) of Influenza Vaccine Antibodies at Day 1- Per Protocol Analysis Set (PPAS)

Time frame: Day 1 (pre-vaccination). Geometric mean (95% Confidence Interval). Unit: titers

Measure	Group 1: Quadrivalent Recombinant Influenza Vaccine (RIV4) n = 145	Group 2: Quadrivalent-inactivated Influenza Vaccine (IIV4) n = 150
A/H1N1	30.8 (24.7 to 38.3)	38.9 (31.7 to 47.7)
A/H3N2	50.1 (40.7 to 61.7)	47.5 (39.1 to 57.6)
B/Victoria	109 (86.6 to 136)	104 (83.2 to 130)
B/Yamagata	237 (185 to 302)	262 (213 to 323)

Population analysed: Analysis was performed on PPAS population that included all randomized participants who received a dose of the study vaccine and had a post-vaccination blood sample. Participants with protocol deviations were excluded from the PPAS.

Primary outcome: Geometric Mean Titers (GMTs) of Influenza Vaccine Antibodies at Day 1- Full Analysis Set (FAS)

Time frame: Day 1 (pre-vaccination). Geometric mean (95% Confidence Interval). Unit: titers

Measure	Group 1: Quadrivalent Recombinant Influenza Vaccine (RIV4) n = 149	Group 2: Quadrivalent-inactivated Influenza Vaccine (IIV4) n = 151
A/H1N1	29.8 (24.0 to 37.1)	38.7 (31.6 to 47.4)
A/H3N2	49.3 (40.1 to 60.6)	47.2 (38.9 to 57.2)
B/Victoria	104 (83.2 to 131)	103 (81.8 to 128)
B/Yamagata	239 (188 to 304)	259 (210 to 319)

Population analysed: Analysis was performed on FAS population that included all randomized participants who received a dose of the study vaccine and had a post-vaccination blood sample. Participants were analyzed according to the intervention to which they were randomized.

Primary outcome: Geometric Mean Titers (GMTs) of Influenza Vaccine Antibodies at Day 29- PPAS

Time frame: Day 29 (post-vaccination). Geometric mean (95% Confidence Interval). Unit: titers

Measure	Group 1: Quadrivalent Recombinant Influenza Vaccine (RIV4) n = 145	Group 2: Quadrivalent-inactivated Influenza Vaccine (IIV4) n = 150
A/H1N1	961 (784 to 1177)	868 (732 to 1030)
A/H3N2	643 (529 to 781)	378 (321 to 445)
B/Victoria	646 (523 to 798)	490 (413 to 580)
B/Yamagata	1268 (1072 to 1499)	897 (782 to 1029)

Population analysed: Analysis was performed on PPAS population.

Primary outcome: Geometric Mean Titers (GMTs) of Influenza Vaccine Antibodies at Day 29- FAS

Time frame: Day 29 (post-vaccination). Geometric mean (95% Confidence Interval). Unit: titers

Measure	Group 1: Quadrivalent Recombinant Influenza Vaccine (RIV4) n = 149	Group 2: Quadrivalent-inactivated Influenza Vaccine (IIV4) n = 151
A/H1N1	955 (783 to 1164)	863 (728 to 1022)
A/H3N2	649 (535 to 787)	379 (323 to 446)
B/Victoria	640 (520 to 788)	486 (410 to 576)
B/Yamagata	1268 (1076 to 1495)	899 (784 to 1031)

Population analysed: Analysis was performed on FAS population.

Adverse events

Time frame: Unsolicited AE data were collected from Day 1 up to 28 days post-vaccination. Solicited reaction data were collected within 7 days post-vaccination. SAEs data were collected from Day 1 up to 6 months post-vaccination (i.e., up to Day 181). Other adverse events reported at 5% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Group 1: Quadrivalent Recombinant Influenza Vaccine (RIV4)	0 of 149 (0%)	96 of 149 (64.4%)	0 of 149
Group 2: Quadrivalent-inactivated Influenza Vaccine (IIV4)	0 of 151 (0%)	100 of 151 (66.2%)	0 of 151

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 11 Sep 2025.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Derived from this study: PubMed 40752250Choi WS, Lee J, Ottaviano C, Samson S, Peng L, Shin S, Choe S, Kim WJ. Immunogenicity and safety of quadrivalent recombinant influenza vaccine in Korean adults: Phase III, randomized study. Vaccine. 2025 Aug 30;62:127521. doi: 10.1016/j.vaccine.2025.127521. Epub 2025 Aug 5.
VAP00016 Plain Language Results SummaryLink provided by the sponsor.
Individual participant dataSharing planned: Yes. Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org

Related trials for Influenza (Healthy Volunteers)

RecruitingObservational study
Screening for LID Clinical Studies Unit Healthy Volunteer Protocols
Zika, Influenza
RecruitingPhase 1
A Trial to Evaluate the Effect of CD388/MK1406 on the Immunogenicity of Fluzone® HD Vaccine (CD388.SQ.1.08/MK-1406-007)
Healthy Participants
Active, not recruitingPhase 3
A Clinical Study to Evaluate the Safety, Tolerability, and Immunogenicity of VAX-31 With Influenza Vaccine in Adults ≥ 50 Years of Age
Pneumococcal Disease
Not yet recruitingPhase 3
Study of a Combination SARS-CoV-2 Recombinant Spike and High-Dose Inactivated Influenza Vaccine With Matrix-M Adjuvant in Adult Participants 60 Years of Age and Older
Immunization, Healthy Volunteers
RecruitingObservational study
Post-marketing Surveillance Study for the Safety of Efluelda® Pre-filled Syringe
Influenza Immunization, Healthy Volunteers

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.

The record lists no contact. Use the official record to reach the sponsor.

3 sites in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

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 7 inclusion and 16 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 11 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 3 sites in South Korea. 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 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 29 Sep 2023). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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 Titers (GMTs) of Influenza Vaccine Antibodies at Day 1- Per Protocol Analysis Set (PPAS) (time frame: Day 1 (pre-vaccination)). The study lists 17 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05144945, which also lists 1 linked publication.

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 11 Sep 2025.