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AzTrials

Influenza VaccinePhase 4NCT07710586

Preliminary Safety Assessment of a Quadrivalent Subunit Influenza Vaccine in China

A Phase 4 study testing quadrivalent subunit influenza vaccine in people with Influenza Vaccine, run by Ab&B Bio-tech Co., Ltd.JS at 2 sites in China.

Completed

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

Official record
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Trial summary

This study evaluates the safety of the quadrivalent subunit influenza vaccine in individuals aged 3 years and older in Jiangsu Province, China. The primary objectives are to assess the occurrence of very rare adverse reactions (incidence <0.01%), investigate the incidence of cerebral infarction following vaccination… Read more about this study

Who is it for?
Ages 3 years and olderHealthy volunteers can take part
Conditions the study is for
Influenza Vaccine
What is being tested?
quadrivalent subunit influenza vaccine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
3,105 participants
Where
2 sitesChina
Study dates
15 Nov 2024to 29 May 2025
Phase
Phase 4
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 3 years and older
  • All sexes
  • Healthy volunteers accepted
  • Child, Adult, Older adult

Who may be able to join

  • Healthy individuals aged 3 years or above.
  • The participant (and/or their guardian/legal representative) has provided informed consent, voluntarily agreed to participate, signed the Informed Consent Form, and is able to comply with the requirements of this study protocol.

Who cannot join

  • Individuals with a known allergy to any component of the vaccine, including eggs, excipients, formaldehyde, or Triton N-101.
  • Individuals suffering from an acute illness, severe chronic disease, an acute exacerbation of a chronic disease, common cold, or fever.
  • Individuals with uncontrolled epilepsy or other progressive neurological disorders, or a history of Guillain-Barré syndrome.
  • Any other condition considered by the investigator as inappropriate for participation in this study.

Trial locations and contacts

2 sites in 1 country.

China2 sites
  • Dongtai Center for Disease Control and Prevention

    Dongtai, Jiangsu, 224200

  • Lianshui County Center for Disease Control and Prevention

    Lianshui, Jiangsu, 223400

Other trials in China

About this study

Official title: Preliminary Safety Assessment of a Quadrivalent Subunit Influenza Vaccine Following Post-Marketing in China: An Open-Label, Single-Arm Clinical Trial

This study evaluates the safety of the quadrivalent subunit influenza vaccine in individuals aged 3 years and older in Jiangsu Province, China. The primary objectives are to assess the occurrence of very rare adverse reactions (incidence <0.01%), investigate the incidence of cerebral infarction following vaccination, and evaluate the incidence of systemic adverse events among participants aged 9 to 17 years.

Read the detailed description

This is an open-label, single-arm, non-controlled, real-world safety study of the quadrivalent subunit influenza vaccine, designed to systematically track and evaluate the overall safety profile following vaccine administration.

The core objectives of this study are as follows:

  1. To assess the occurrence of rare adverse reactions with an incidence rate of less than 0.01% after vaccination;
  2. To investigate the incidence of cerebral infarction events following receipt of the study vaccine;
  3. To evaluate the incidence of systemic adverse events after vaccination among participants aged 9 to 17 years.

A total of 3,105 eligible participants aged 3 years and older who voluntarily receive the vaccine will be enrolled. All enrolled participants will be administered a single 0.5 mL intramuscular dose of the quadrivalent influenza subunit vaccine.

The safety monitoring protocol is arranged as follows:

  1. 30-minute immediate observation: On-site monitoring will be conducted at the vaccination clinic immediately after injection to detect immediate adverse reactions.
  2. 28-day systematic safety follow-up: Participants will perform daily self-monitoring of adverse events within 28 days after vaccination. Investigators will conduct two on-site centralized follow-up visits on Day 7 and Day 28 post-vaccination respectively, to verify and collect adverse event data.
  3. 6-month serious adverse event monitoring: The occurrence of serious adverse events will be monitored via spontaneous reporting by participants within 6 months after vaccination.
Being tested
quadrivalent subunit influenza vaccine
Keywords
safety, Quadrivalent Subunit Influenza Vaccine
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 subunit influenza vaccineBiological

    one dose of quadrivalent subunit influenza vaccine

Study groups in NCT07710586
Study groupRoleWhat they receive
The quadrivalent influenza subunit vaccine GroupExperimentalreceive a single 0.5 mL intramuscular dose of the quadrivalent influenza subunit vaccine
Receives: Biological: quadrivalent subunit influenza vaccine

What is being measured

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

  1. Adverse Events (AEs)

    Occurrence of adverse events (AEs) within 30 minutes, 7 days, and 28 days after vaccination

    Measured: 30 minutes, 7 days, and 28 days after vaccination

  2. Adverse Drug Reactions(ADR)

    Incidence of known adverse drug reactions (ADRs) within 30 minutes, 7 days, and 28 days after vaccination

    Measured: 30 minutes, 7 days, and 28 days after vaccination

  3. Serious Adverse Events (SAEs)

    Occurrence of serious adverse events (SAEs) within 6 months after vaccination; Incidence of new adverse reactions following vaccination; Incidence of cerebral infarction following vaccination; Incidence of systemic adverse reactions following vaccination in individuals aged 9 to 17 years

    Measured: 6 months after vaccination

Timeline

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

  1. First posted17 Jul 2026
  2. Study start15 Nov 2024
  3. Primary completion29 May 2025
  4. Study completion29 May 2025

Resources

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 4
Primary purpose
Prevention
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
3,105 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07710586
Sponsor's protocol ID
CTR20244333
Status last verified
Jul 2026
First submitted
14 Jul 2026
Last updated
20 Jul 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing quadrivalent subunit influenza vaccine in people with Influenza Vaccine, run by Ab&B Bio-tech Co., Ltd.JS at 2 sites in China.

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 2 inclusion and 4 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 20 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in China. 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 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

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?

Adverse Events (AEs) (time frame: 30 minutes, 7 days, and 28 days after vaccination). The study lists 3 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 20 Jul 2026.

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