Tfh-targeting genetic vaccine adjuvant to boost long-lasting COVID immunity

A Phase 1/2a, randomized study of a Tfh-targeting genetic vaccine adjuvant designed to induce broad, durable immune responses

['FUNDING_U01'] · UNIVERSITY OF CALIFORNIA LOS ANGELES · NIH-11332659

A genetic vaccine add-on aims to engage helper immune cells so people develop broader, longer-lasting antibodies against SARS‑CoV‑2.

Quick facts

Phase['FUNDING_U01']
Study typeNih_funding
SexAll
SponsorUNIVERSITY OF CALIFORNIA LOS ANGELES (nih funded)
Locations1 site (LOS ANGELES, UNITED STATES)
Trial IDNIH-11332659 on ClinicalTrials.gov

What this research studies

This early-phase randomized trial is testing an adjuvant called “s3” that links an anti-CD3 antibody fragment to a viral immunogen delivered in a low-dose Ad35 vector. Adult volunteers will receive the vaccine and be followed for safety, antibody levels, and mucosal immune responses over time. The approach is designed to recruit T follicular helper cells to help B cells produce stronger, wider-ranging neutralizing antibodies, building on promising macaque data showing durable responses. Study visits will include blood draws and likely nasal or saliva samples to measure durability and breadth against variants.

Who could benefit from this research

Good fit: Adults who meet the health and eligibility criteria for an early-phase vaccine trial and can attend visits at the UCLA site.

Not a fit: People with active COVID-19 infection, certain immune-suppressing conditions, or known contraindications to adenoviral vectors may not be eligible or likely to benefit.

Why it matters

Potential benefit: If successful, this could produce vaccines that protect against more variants for much longer, reducing the need for frequent boosters.

How similar studies have performed: Animal studies showed the s3 approach produced high, stable neutralizing antibodies for over 10 months, but this specific Tfh-targeting adjuvant is novel in human trials.

Where this research is happening

LOS ANGELES, UNITED STATES

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.

View on NIH RePORTER →

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.