Flu shot showdown: Cell-Grown vs recombinant vaccine put to the test

NCT ID NCT06518577

Completed ⭐️ VACCINE ⭐️ Sponsor: Duke University Source: ClinicalTrials.gov ↗

First seen Jul 28, 2026 · Last updated Jul 29, 2026 · Updated 1 time

Summary

This study compares two approved flu vaccines—Flucelvax (made in animal cells) and Flublok (made using a recombinant protein)—in adults aged 18 to 64. Researchers will measure immune responses from blood samples taken before vaccination, one month later, and six months later. The goal is to see which vaccine triggers stronger and longer-lasting protection against circulating influenza viruses.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance: two approved influenza vaccines: Flucelvax (cell culture-based) and Flublok (recombinant protein-based)
What this could lead to: If one vaccine proves more effective, it could guide future flu shot recommendations and improve protection against circulating strains.
What could go wrong: This is a phase 4 immunogenicity study, not designed to measure actual illness reduction. Results may not translate to real-world effectiveness.

This is an AI summary of the original study and may miss details. Read our disclaimer.

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Conditions

The condition(s) this trial relates to.

influenza prevention target

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

INFLUENZA

Contacts and locations

Locations

ASU Biodesign Institute

Tempe, Arizona, 85281, United States
Centers for Disease Control and Prevention

Atlanta, Georgia, 30333, United States
Department of Family Medicine, University of Pittsburgh School of Medicine

Pittsburgh, Pennsylvania, 15260, United States
University Hospitals Cleveland Medical Center

Cleveland, Ohio, 44106, United States
VA Northeast Ohio Healthcare System (VANEOHS)

Cleveland, Ohio, 44106, United States
Valleywise Health Comprehensive Health Center

Phoenix, Arizona, 85008, United States
Washington University IDCRU

St Louis, Missouri, 63110, United States

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