Could a smaller dose of monkeypox vaccine work just as well?

NCT ID NCT05512949

Completed ⭐️ VACCINE ⭐️ Sponsor: National Institute of Allergy and Infectious Diseases (NIAID) Source: ClinicalTrials.gov ↗

First seen Jun 26, 2026 · Last updated Jun 27, 2026 · Updated 1 time

Summary

This study tested whether giving a smaller dose of the MVA-BN (JYNNEOS) monkeypox vaccine under the skin works as well as the standard full dose given into the muscle. About 229 healthy adults aged 18 to 50 received either one-fifth or one-tenth of the standard dose under the skin, or the full dose into the muscle. Researchers measured immune responses to see if the lower doses were non-inferior to the standard regimen.

What this could mean

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

Active substance: MVA-BN vaccine (JYNNEOS)
What this could lead to: If successful, this could show that smaller doses of the monkeypox vaccine given under the skin are just as effective, allowing more people to be vaccinated with the same supply.
What could go wrong: This is a Phase 2 trial with only 229 healthy adults, so results may not apply to everyone. Lower doses might not provide the same level of protection as the standard dose.

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.

monkeypox prevention target

As listed by the trial registrant

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

MONKEYPOX

Contacts and locations

Locations

Baylor College of Medicine

Houston, Texas, 77030-3411, United States
Brigham and Women's Hospital

Boston, Massachusetts, 02115-6110, United States
George Washington University Medical Faculty Associates

Washington D.C., District of Columbia, 20037, United States
NIH Clinical Research Center, Investigational Drug Management and Research Section

Bethesda, Maryland, 20892-1504, United States
Saint Louis University Center for Vaccine Development

St Louis, Missouri, 63104-1015, United States
The Hope Clinic of Emory University

Decatur, Georgia, 30030, United States
University of California, San Diego (UCSD) - Antiviral Research Center (AVRC)

San Diego, California, 92103-8208, United States
Vanderbilt University Medical Center

Nashville, Tennessee, 37212, United States

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