> Trialight public data. Index of pages: https://trialight.com/llms.txt
> Web page: https://trialight.com/data/trial/a-phase-iii-clinical-trial-of-quadrivalent-influenza-vaccine-03a7e93e-7961-4a78-91a9-6a671e95dece
> Record changed: 2026-10-13

# A Phase III Clinical Trial of Quadrivalent Influenza Vaccine in Healthy Subjects Aged 6 to 35 Months

NCT06049927

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

Phase

Phase 3

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

Recruitment status

Completed

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

Participants

3,300

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

Lead sponsor

Sinovac Biotech Co., Ltd

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

Start date

2023-09-16

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

Number of sites

5

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

## Title and summary

**Summary**

A phase III clinical trial of the study of quadrivalent influenza vaccine developed by Sinovac Biotech will be conducted in Chinese children aged 6 to 35 months. The trial is an randomized, double-blind and active controlled study. The objective of this study is to evaluate the Immunogenicity and safety of the vaccine.

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Short title**

A Phase III Clinical Trial of Quadrivalent Influenza Vaccine in Healthy Subjects Aged 6 to 35 Months

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Official title**

An Randomized, Double-blind, Controlled Phase III Clinical Trial to Evaluate the Safety and Immunogenicity of Quadrivalent Influenza Vaccine in Healthy Subjects Aged 6 to 35months

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

## Status and phase

**Control arm**

Active comparator

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Registry reports results**

No

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Listing at source**

Listed

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Recruitment status**

Completed

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Phase**

Phase 3

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Study type**

Interventional

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

## Dates

**Completion date**

2024-05-23

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**First posted**

2023-09-22

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Registry last updated**

2025-08-14

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Primary completion date**

2024-05-23

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Start date**

2023-09-16

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

## Size and sites

**Actual participants**

3,300

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Participants**

3,300

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Participant count basis**

Actual

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Protocol amendments**

3

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Randomisation ratio**

2:2:1:1

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Number of sites**

5

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

## Sponsor and oversight

**Data monitoring committee**

No

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Registry sponsor category**

Industry

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Lead sponsor**

Sinovac Biotech Co., Ltd

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Source registry**

ClinicalTrials.gov

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

## Identifiers

**Registry ID**

NCT06049927

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**ClinicalTrials.gov ID**

NCT06049927

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

**Registry record**

Open registry record

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

## Study design

**Allocation**

Randomised

**Model**

Parallel groups

**Purpose**

Prevention

**Masking**

Quadruple masking

**Masked roles**

Participants, Care providers, Investigators, Outcome assessors

Sources for study design

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

## Outcomes

### Primary outcomes

1. Seroconversion rates of HI antibody  
Timeframe: 28 days after full schedule immunization  
Anti-influenza antibodies were measured using HAI assay for 4 strains: H1N1, H3N2, B Victoria and B Yamagata. Seroconversion was defined as pre-vaccination titer \\<1：10 and post-vaccination titer ≥1:40, and Significant increase was defined as pre-vaccination titer≥1:40 and ≥ 4-fold increase of post-vaccination titer.
2. Geometric Mean Titers (GMTs) of HI antibody  
Timeframe: 28 days after full schedule immunization  
Anti-influenza antibody levels were measured using hemagglutination inhibition (HAI) assay for 4 strains: H1N1, H3N2, B Victoria, B Yamagata.
3. Number of Participants With Seroprotection to Influenza Vaccine Antigens  
Timeframe: 28 days after full schedule immunization  
Anti-influenza antibodies were measured using HAI assay for 4 strains: H1N1, H3N2, B Victoria and B Yamagata. Seroprotection was defined as an antibody titer ≥1:40 at pre-vaccination and at post-final vaccination.

### Secondary outcomes

1. GMIs of HI antibody  
Timeframe: 28 days after full schedule immunization  
Anti-influenza antibody were measured using hemagglutination inhibition (HAI) assay for 4 strains: H1N1, H3N2, B Victoria, B Yamagata. GMI is the increase fold of GMT post vaccination compared with pre vaccination
2. Incidence of adverse reactions  
Timeframe: 0-30 days after each dose  
Incidence of adverse reaction 0-30 days after each dose
3. Incidence of adverse reactions  
Timeframe: 0-7 days after each dose  
Incidence of adverse reaction 0-7 days after each dose
4. Incidence of Serious adverse events  
Timeframe: Since the beginning of vaccination until 6 months after the last dose  
Incidence of serious adverse events from beginning of vaccination until 6 months after the last dose
5. Incidence of AESI  
Timeframe: since the beginning of vaccination until 6 months after the last dose  
Incidence of AESI since the beginning of vaccination until 6 months after the last dose

Sources for outcomes

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

## Eligibility

**Sex**

All

**Age groups**

Children

**Minimum age**

6 Months

**Maximum age**

35 Months

**Healthy volunteers**

Yes

### Inclusion criteria

- Healthy infants aged 6-35 months;
- Proven vaccination certificate and birth certificate;
- The subjects' guardians can understand and voluntarily sign the informed consent form.

### Exclusion criteria

- Received any circulating seasonal influenza vaccine prior to enrollment or had an influenza vaccine schedule during the study;
- Suffering from seasonal influenza in the past 6 moths;
- Axillary temperature >37.0°C;
- History of allergy to the vaccine or vaccine components, or serious adverse reactions to the vaccine, such as urticaria, dyspnea, angioedema and asthma;
- Congenital malformations or developmental disorders, genetic defects, severe malnutrition, etc.;
- Severe chronic diseases(Such as down syndrome, diabetes, sickle cell anaemia or neurological disorders);
- Severe neurological disease (epilepsy, convulsions or convulsions) or mental illness;
- Autoimmune disease (such as systemic lupus erythematosus) or immunodeficiency / immunosuppression (such as HIV, after organ transplantation)
- Thyroid disease or history of thyroidectomy, asplenia,functional asplenia, asplenia or splenectomy resulting from any condition;
- Diagnosed abnormal blood coagulation function (eg, lack of blood coagulation factors, blood coagulopathy, abnormal platelets) or obvious bruising or blood coagulation;
- Continuous use of corticosteroids or other immunosuppressive agents for ≥ 14 days within the past 6 months (excluding allergic rhinitis corticosteroid spray therapy, acute noncomplicated dermatitis superficial corticosteroid therapy) and cytotoxic therapy in the past 6 months;
- Acute diseases or acute exacerbation of chronic diseases in the past 3 days;
- Receipt of blood products within in the past 3 months;
- Receipt of other investigational drugs in the past 30 days;
- Receipt of attenuated live vaccines in the past 14 days;
- Receipt of inactivated or subunit vaccines in the past 7 days;
- Participated in other clinical trials before enrollment and in the follow-up period, or plans to participate in other clinical trials during the clinical trial;
- According to the investigator's judgment, the subject has any other factors that are not suitable for participating in the clinical trial

Sources for eligibility

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

## Sites

- Huoqiu County Center for Disease Control and PreventionLu'an, China
- Zhushan County Center for Diseases Control and PreventionShiyan, China
- Nanzhang County Center for Disease Prevention and ControlXiangyang, China
- Laohekou Center for Disease Control and PreventionXiangyang, China
- Zigui County Center for Disease Control and PreventionYichang, China

Sources for sites

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

## References

- PubMed 41391373  
Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/41391373/)
Related publication

Sources for references

Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06049927)

## Related records

### Drugs (1)

- [Brentuximab vedotin](https://trialight.com/data/asset/brentuximab-vedotin-b112eac4-7573-41dc-af6c-6c9212132a79.md)

### Lead sponsors (1)

- [Sinovac Biotech Co., Ltd](https://trialight.com/data/company/sinovac-biotech-co-ltd-b7e4da39-2d80-4892-af21-d322850517aa.md)

### Targets (16)

- [TNFRSF8](https://trialight.com/data/target/tnfrsf8-ea5051a6-2140-593b-8c7d-ffc4c956dc5d.md)
- [TUBA1A](https://trialight.com/data/target/tuba1a-f463ed42-1a60-5499-a9d4-1b9bf58dc1a0.md)
- [TUBA1B](https://trialight.com/data/target/tuba1b-9d713a5c-e5d0-50cb-852e-c74562888bab.md)
- [TUBA1C](https://trialight.com/data/target/tuba1c-308bfde0-cfab-509b-8c74-457db8c8b365.md)
- [TUBA3C](https://trialight.com/data/target/tuba3c-4abfb5fd-1449-5948-844d-76d4c28b3ca5.md)
- [TUBA3E](https://trialight.com/data/target/tuba3e-3cb5d4e3-43d1-5066-b94a-f3fe2b9f7812.md)
- [TUBA4A](https://trialight.com/data/target/tuba4a-5a3e4e1b-bf84-5903-89e9-0dda280376ab.md)
- [TUBB](https://trialight.com/data/target/tubb-ec240191-c297-5eba-9021-60488341c8f3.md)
- [TUBB1](https://trialight.com/data/target/tubb1-aea59905-0cc2-5a62-be89-e62ea633ec75.md)
- [TUBB2A](https://trialight.com/data/target/tubb2a-d05cd610-e1d8-5bbe-a299-897fd869fa9f.md)
- [TUBB2B](https://trialight.com/data/target/tubb2b-23c4b067-2275-52fa-8ab9-3c15fac539bb.md)
- [TUBB3](https://trialight.com/data/target/tubb3-2961b200-1591-50aa-93ae-4a54a10915e9.md)
- [TUBB4A](https://trialight.com/data/target/tubb4a-ad5f7184-fd22-58b7-a66c-95289ce2e093.md)
- [TUBB4B](https://trialight.com/data/target/tubb4b-1b93a23c-a19e-5d34-93be-30d58939e047.md)
- [TUBB6](https://trialight.com/data/target/tubb6-9f2941d7-b631-5e8b-b148-6bde2a6caf22.md)
- [TUBB8](https://trialight.com/data/target/tubb8-f8700f93-4301-5eda-9407-55f76aa16a06.md)

---

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