Influenza Vaccination After Acute Coronary Syndrome (InVaACS)

The goal of this clinical trial is to learn if influenza vaccination can prevent adverse cardiac events in Chinese acute coronary syndrome patients. The main questions it aims to answer are:

• Whether influenza vaccination can decrease events of cardiovascular death, MI, or stroke?
• Whether influenza vaccination can decrease events of all cause death, unplanned revascularization, unplanned hospitalization for heart failure or for arrhythmia, stent thrombosis?

If there is a comparison group: Researchers will compare influenza vaccination and placebo to see if adverse cardiac events decrease.

Participants will receive an influenza vaccination or placebo after enrollment and phone calls for follow-up at 1 month, 3 months, 6 months and 1 year after discharge.

Study Overview

• Status: Recruiting
• Conditions: Acute Coronary Syndromes (ACS)
• Intervention / Treatment: Drug: Influenza vaccine; Drug: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 6620
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Yang Sun; Phone Number: +86-15527674573; Email: sunyang.7@163.com

Study Locations

• China
  • Hubei
    • Wuhan, Hubei, China, 430030
      • Recruiting
      • Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology
      • Contact: Yang Sun, MD; Phone Number: 86-15527674573; Email: sunyang.7@163.com
      • Principal Investigator: Dao Wen Wang, MD, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. ACS patient aged from 18 to 80 years.
2. Volunteer for the study and written informed consent.

Exclusion Criteria:

1. Participate in any drug clinical trials within 3 months.
2. Patients with life-threatening complications, or the researchers determined that the survival time of patients with no more than 1 years.
3. Serious neurological disease (Alzheimer's disease, Parkinson syndrome, progressive lower limbs or deaf patients).
4. Previous history of cancer or tumor, or pathological examination confirmed precancerous lesions (such as breast ductal carcinoma in situ, or atypical hyperplasia of the cervix).
5. Patients refused to comply with the requirements of this study to complete the research work.
6. Patients Received influenza vaccination within 1 year.
7. Patients with contraindications for influenza vaccination.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: influenza vaccination; patients will receive influenza vaccination	Drug: Influenza vaccine; Patients receive injection of 0.5ml influenza vaccine
Placebo Comparator: placebo; patients will receive placebo (PBS)	Drug: Placebo; Patients will receive injection of 0.5ml PBS

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Composite endpoint of cardiovascular death, myocardial infarction or stroke	The number of participants with cardiovascular death, myocardial infarction or stroke (first occurring) till 12 months.	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
all cause death	The number of participants with all cause death till 12 months	12 months
cardiovascular death	The number of participants with cardiovascular death till 12 months	12 months
stroke	The number of participants with stroke till 12 months	12 months
myocardial infarction	The number of participants with myocardial infarction till 12 months	12 months
unplanned hospitalization for heart failure or for arrhythmia	The number of participants with unplanned hospitalization for heart failure or for arrhythmia till 12 months	12 months
unplanned revascularization	The number of participants with unplanned revascularization till 12 months	12 months
stent thrombosis	The number of participants with stent thrombosis till 12 months	12 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
influenza like illness	The number of participants with fever (body temperature ≥38℃) accompanied by cough or sore throat till 12 months	12 months
hospitalization for influenza	The number of participants with hospitalization for influenza till 12 months	12 months

Collaborators and Investigators

• Sponsor: Tongji Hospital
• Investigators: Principal Investigator: Dao Wen Wang, Tongji Hospital

Study record dates

Study Major Dates

• Study Start (Actual): December 3, 2025
• Primary Completion (Estimated): March 30, 2029
• Study Completion (Estimated): March 30, 2029

Study Registration Dates

• First Submitted: November 21, 2025
• First Submitted That Met QC Criteria: November 21, 2025
• First Posted (Estimated): December 2, 2025

Study Record Updates

• Last Update Posted (Actual): January 13, 2026
• Last Update Submitted That Met QC Criteria: January 10, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Heart Diseases; Myocardial Ischemia; Acute Coronary Syndrome; Biological Products; Complex Mixtures; Vaccines; Viral Vaccines; Influenza Vaccines
• Other Study ID Numbers: InVaACS

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
• product manufactured in and exported from the U.S.: No