Clinical Trial of Quadrivalent Subunit Influenza Vaccine (Adjuvant) in Chinese Population Aged 65 Years and Older

February 12, 2026 updated by: Ab&B Bio-tech Co., Ltd.JS

A Randomized, Blinded, Controlled Phase I Clinical Trial to Evaluate the Safety of a Quadrivalent Subunit Influenza Vaccine (Adjuvant) in Adults Aged 65 Years and Older

The objective of this study was to evaluate the safety of quadrivalent subunit influenza vaccine (adjuvant) in people aged 65 years and older.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
80

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • China
    • Hubei
      • Shiyan, Hubei, China
        • Yunxi County Center for Disease Control and Prevention

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Age at enrollment is ≥65 years (including the 65th birthday).
  • The participant voluntarily agrees to take part in the trial and has signed the informed consent form.
  • The participant is able to comply with the trial follow-up schedule as required by the protocol (i.e., no plans for long-term absence or relocation from the study site).
  • Medically stable: The participant may have underlying chronic conditions such as hypertension, diabetes, ischemic heart disease, or hypothyroidism, but symptoms/signs must be controlled. If the participant is on any medication, the dosage must have remained stable for at least three weeks prior to vaccination.

Exclusion Criteria:

  • Axillary temperature >37.0°C.
  • Confirmed influenza virus infection by laboratory test or self-test kit positive within the past 12 months.
  • Received any influenza vaccine (licensed or investigational) within the past 12 months or plans to receive any influenza vaccine during the study.
  • Known or suspected allergic to any component of the investigational vaccine.
  • A history of severe allergic reactions to any vaccines or medications (for example, but not limited to: anaphylactic shock, allergic laryngeal edema, allergic purpura, thrombocytopenic purpura, local allergic necrotic reaction (Arthus reaction)).
  • Congenital malformations or developmental disorders, and genetic defects or severe malnutrition.
  • History of convulsions or seizures, epilepsy, psychiatric disorders, or relevant family history.
  • Severe liver and kidney diseases, malignant tumors, various acute diseases, or being in the acute exacerbation stage of a chronic disease.
  • Diagnosed with congenital or acquired immunodeficiency, HIV infection, lymphoma, leukemia, or other immune-mediated/autoimmune diseases.
  • A history of asthma, unstable within the past two years requiring emergency treatment, hospitalization, intubation, or oral/intravenous corticosteroids.
  • Individuals who have received immunostimulant or immunosuppressant therapy within the past 6 months (continuously administered orally or via drip infusion for more than 14 days).
  • Suffering from severe cardiovascular diseases (e.g., heart disease, cor pulmonale, pulmonary edema).
  • Blood pressure ≥150/100 mmHg despite medication control.
  • History of live attenuated vaccine within 28 days prior to vaccination, or any other vaccine within 14 days prior to vaccination.
  • Diagnosed with progressive neurological diseases, or a history of Guillain-Barré syndrome.
  • Asplenia or functional asplenia, including splenectomy due to any reason, or resection/partial removal of other vital organs.
  • Received blood or blood-derived products within the past 6 months.
  • A diagnosed history of coagulation disorders (e.g., coagulation factor deficiencies, coagulopathies, platelet disorders).
  • Currently undergoing anti-tuberculosis treatment.
  • Clinically significant abnormalities in laboratory tests (blood biochemistry, blood routine and urine routine) as determined by the investigator.
  • Any condition that, in the opinion of the investigator, makes the participant unsuitable for this clinical trial.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Placebo Comparator: Placebo
Biological: 0.9% sodium chloride injection (normal saline)
A single 0.5 mL dose is administered intramuscularly into the deltoid muscle of the upper arm on Day 0.
Experimental: Low-dose experimental vaccine
Biological: Quadrivalent Subunit Influenza Vaccine (Adjuvant)
A single 0.25 mL dose is administered intramuscularly into the deltoid muscle of the upper arm on Day 0.
Biological: Quadrivalent Subunit Influenza Vaccine (Adjuvant)
A single 0.5 mL dose is administered intramuscularly into the deltoid muscle of the upper arm on Day 0.
Experimental: High-dose experimental vaccine
Biological: Quadrivalent Subunit Influenza Vaccine (Adjuvant)
A single 0.25 mL dose is administered intramuscularly into the deltoid muscle of the upper arm on Day 0.
Biological: Quadrivalent Subunit Influenza Vaccine (Adjuvant)
A single 0.5 mL dose is administered intramuscularly into the deltoid muscle of the upper arm on Day 0.
Other: Adjuvant
Biological: MF59
A single 0.5 mL dose is administered intramuscularly into the deltoid muscle of the upper arm on Day 0

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Incidence of adverse events (AEs) or reactions (ARs) within 30 minutes post-vaccination
Time Frame: Within 30 minutes post-vaccination
Within 30 minutes post-vaccination
Incidence of adverse events (AEs) or reactions (ARs) within 0-7 days post-vaccination
Time Frame: Within 0-7 days post-vaccination
Within 0-7 days post-vaccination
Incidence of adverse events (AEs) or reactions (ARs) within 0-28 days post-vaccination
Time Frame: Within 0-28 days post-vaccination
Within 0-28 days post-vaccination
The incidence of laboratory abnormalities (including blood biochemistry, blood routine and urine routine ) on Day 3 post-vaccination.
Time Frame: On Day 3 post-vaccination
On Day 3 post-vaccination
The incidence of serious adverse events (SAEs) and Adverse Events of Special Interest (AESI) within 12 months post-vaccination.
Time Frame: Within 12 months post-vaccination.
Within 12 months post-vaccination.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Ab&B Bio-tech Co., Ltd.JS

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Yither Biotech Co., Ltd

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Yeqing Tong, Doctor, Hubei Provincial Center for Disease Control and Prevention

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 13, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 13, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 13, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 13, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 12, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 19, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 19, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 12, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • aQIV-ZHSW-01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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