Effect of Oral Supplement on Influenza Vaccine Long-term Response

Sponsor
Tsinghua University
Study ID
NCT07357467
Status
Not Yet Recruiting

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Conditions

  • Immunosenescence
  • Influenza

Eligibility Criteria

Sex
ALL
Age
60 Years - 70 Years
Healthy Volunteers
Accepted

Study Details

This is a follow-up study of a previously completed randomized controlled trial (NCT06827873) that investigated the effects of oral supplements on influenza vaccine response in adults aged 60-70 years. The original study was completed in April 2025, with participants receiving either TUDCA (Tauro Ursodesoxy Cholic Acid) supplementation, fatty acid supplementation, or placebo during influenza vaccination. The primary objectives of this follow-up study are to: 1. Evaluate the durability of vaccine-induced antibody responses approximately 8 months post-vaccination 2. Assess the persistence of immune memory cells, particularly long-lived plasma cells and memory B cells 3. Compare long-term immune responses between the TUDCA supplementation group and placebo group This observational follow-up involves a single visit where participants will: 1. Provide one blood sample for antibody and immune cell analysis 2. No intervention or vaccination will be administered The study will specifically focus on B cell subsets through flow cytometry analysis, including total B cells, memory B cells, plasma cells, and long-lived plasma cells. This research aims to determine whether TUDCA supplementation can enhance the durability of vaccine-induced immunity in older adults.

Key Dates

First listed
Jan 22, 2026
Start date
Mar 31, 2026
Status verified
Jan 2026
Primary completion
May 31, 2026
Completion
Jul 31, 2026

Study Design

Enrollment
30 participants (estimated)

Arms

  • Arm: TUDCA Supplementation Group
    Participants who received TUDCA supplementation (1000 mg/day) during the original study (February-April 2025). In the original trial, participants took 1000 mg of TUDCA (Tauroursodeoxycholic acid) dietary supplement capsules daily. Each capsule contained 500 mg of TUDCA (two capsules per serving). Participants maintained their usual lifestyle during the intervention: Day 0-Day 2 served as an adaptation period; on Day 3, they received a quadrivalent influenza vaccine, followed by continued supplementation until Day 24. This extended follow-up study involves no intervention, only a single fasting blood draw (20 mL) approximately 12 months post-vaccination to assess long-term immune responses.
  • Arm: Placebo Group
    Participants who received placebo during the original study (February-April 2025). In the original trial, participants took placebo capsules identical in appearance and smell to the TUDCA capsules. Participants maintained their usual lifestyle during the intervention: Day 0-Day 2 served as an adaptation period; on Day 3, they received a quadrivalent influenza vaccine, followed by continued placebo supplementation until Day 24. This extended follow-up study involves no intervention, only a single fasting venous blood draw (approximately 20 mL) about 12 months post-vaccination to assess long-term immune responses.

Primary Outcome Measure

Long-term Influenza-Specific Antibody Levels Post-Vaccination [ Time Frame: Day 360 (approximately 12 months post-vaccination) ]

Central Contacts

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