New Exosome-Based COVID booster enters human testing

NCT ID NCT07095231

First seen Jun 24, 2026 · Last updated Jun 27, 2026 · Updated 1 time

Summary

This early-stage trial tested a new COVID-19 booster vaccine, STX-S, in 60 healthy adults who had already received a primary vaccine series and at least one booster. The vaccine uses tiny particles called exosomes to deliver spike proteins. The main goal was to check safety and side effects at three different doses, while also measuring immune responses in the blood and nose.

What this could mean

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

Active substance

STX-S (an experimental vaccine using exosomes to deliver spike proteins)

What this could lead to

If successful, this could lead to a new type of COVID-19 booster that may offer better or longer-lasting protection.

What could go wrong

This is a very early Phase 1 trial with only 60 people, so safety and immune response are still unknown. It may not work as hoped or could have side effects.

Disclaimer Read more

This is a summary of the original study . Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.

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Conditions

The condition(s) this trial relates to.

Coronavinae infectious disease COVID-19 prevention target

As listed by the trial registrant

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

Contacts and locations

Locations

  • Kaiser Permanente Washington Health Research Institute

    Seattle, Washington, 98101-1466, United States

  • The University of Washington - Virology Research Clinic

    Seattle, Washington, 98104, United States

  • University of Rochester Medical Center - Vaccine Research Unit

    Rochester, New York, 14642-0001, United States