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

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

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

Study Overview

• Status: Active, not recruiting
• Conditions: Influenza; Influenza Vaccine
• Intervention / Treatment: Biological: Subunit Influenza Vaccine (Adjuvant); Biological: Subunit Influenza Vaccine (Adjuvant); Biological: MF59; Biological: 0.9% sodium chloride injection (normal saline)

• Study Type: Interventional
• Enrollment (Actual): 80
• Phase: Phase 1

Contacts and Locations

Study Locations

• China
  • Hubei
    • Xiangyang, Hubei, China
      • Gucheng county Center for Disease control and Prevention

Participation Criteria

Eligibility Criteria

• 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

How is the study designed?

Design Details

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

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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: 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: 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: 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: 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

Outcome Measure	Time Frame
Incidence of adverse events (AEs) or reactions (ARs) within 30 minutes post-vaccination	Within 30 minutes post-vaccination
Incidence of adverse events (AEs) or reactions (ARs) 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	Within 0-28 days post-vaccination
The incidence of laboratory abnormalities (including blood biochemistry, blood routine and urine routine ) 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.	Within 12 months post-vaccination.

Collaborators and Investigators

• Sponsor: Ab&B Bio-tech Co., Ltd.JS
• Collaborators: Yither Biotech Co., Ltd
• Investigators: Principal Investigator: Yeqing Tong, Doctor, Hubei Provincial Center for Disease Control and Prevention

Study record dates

Study Major Dates

• Study Start (Actual): November 13, 2025
• Primary Completion (Estimated): December 13, 2026
• Study Completion (Estimated): December 13, 2026

Study Registration Dates

• First Submitted: November 13, 2025
• First Submitted That Met QC Criteria: February 12, 2026
• First Posted (Actual): February 19, 2026

Study Record Updates

• Last Update Posted (Actual): February 19, 2026
• Last Update Submitted That Met QC Criteria: February 12, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; Orthomyxoviridae Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases; Influenza, Human; Pharmaceutical Preparations; Chemical Actions and Uses; Inorganic Chemicals; Chlorine Compounds; Crystalloid Solutions; Isotonic Solutions; Solutions; Specialty Uses of Chemicals; Pharmaceutic Aids; Sodium Compounds; Chlorides; Hydrochloric Acid; MF59 oil emulsion; Saline Solution; Adjuvants, Pharmaceutic; Sodium Chloride
• Other Study ID Numbers: aTIV-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