NCT06810934

A Phase 1/2A, Randomized Study of a T Follicular Helper (TFH)-Targeting Genetic Vaccine Strategy Designed to Induce Broad, Durable Immune Responses

• Status: Recruiting
• Phase: Phase 1 / Phase 2
• Study type: Interventional
• Enrollment: 80 (estimated)
• Sponsor: Kara Chew · Academic / Other
• Sex: All
• Age: 40 Years – 64 Years
• Healthy volunteers: Accepted

Summary

The goal of this clinical trial is to test two investigational COVID-19 booster vaccines, called CoTend-s3BXBB and CoTend-BXBB, in healthy volunteers ages 40-64. The CoTend-s3BXBB vaccine includes a component called "s3", which was designed to improve the body's response to the vaccine. CoTend-BXBB is the same vaccine without s3. The main questions the study aims to answer are: 1) Is the investigational vaccine safe? 2) Does "s3" lead to bigger, broader, and longer-lasting responses to the vaccine? 5 different doses of the vaccines will be studied. Participants will receive a single dose of either CoTend-s3BXBB, CoTend-BXBB, or placebo. Participants will be monitored for side effects. Saliva, nasal, and blood samples will be collected and immune responses to the vaccine will be measured.

Conditions

• COVID-19
• SARS-CoV-2 Infection

Interventions

Type	Name	Description
BIOLOGICAL	CoTend-BXBB (SARS2-30404)	Ad35-vectored SARS-CoV-2 RBD (XBB.1.5) vaccine
BIOLOGICAL	CoTend-s3BXBB (SARS2-17032)	Ad35-vectored s3-SARS-CoV-2 RBD (XBB.1.5) vaccine
BIOLOGICAL	Placebo	Sterile sodium chloride 0.9% for injection, preservative free

Timeline

• Start date: 2025-10-21
• Primary completion: 2027-12-01
• Completion: 2029-10-01
• First posted: 2025-02-06
• Last updated: 2025-10-31

Locations

2 sites across 1 country: United States

Regulatory

• FDA-regulated drug study