GeoVax Labs, Inc. (Nasdaq: GOVX) announced on September 21, 2026, the publication of preclinical research demonstrating that a single dose of an enhanced Modified Vaccinia Ankara (MVA) vaccine, designated MVA-X, provided durable protection against lethal orthopoxvirus challenges, including highly pathogenic Clade I mpox virus. The manuscript, titled “Single-dose Efficacy of a Next-Generation Mpox Vaccine Harnessing an Immunomodulatory Peptide,” is available as a preprint on bioRxiv under DOI 10.64898/2026.07.31.742137 and has not yet been peer-reviewed.
The studies, conducted with Washington State University and funded by GeoVax, showed that a single MVA-X vaccination protected animals against lethal and high-dose orthopoxvirus challenge at days 55, 90, and 150 post-vaccination. Protection was comparable to a conventional two-dose MVA regimen. MVA-X also restricted viral replication and systemic dissemination, generated durable antigen-specific CD8+ T-cell responses despite declining antibody levels, and protected highly susceptible animals against lethal Clade I mpox challenge.
These findings matter because currently recommended MVA-based mpox vaccines generally require a two-dose regimen. A single-dose option could simplify deployment, accelerate vaccination campaigns, and reduce logistical burdens during outbreaks, particularly in resource-constrained settings. David Dodd, Chairman and CEO of GeoVax, said, “During an outbreak, reducing a two-dose regimen to a single vaccination could simplify deployment, accelerate completion of vaccination programs and reduce the logistical burden associated with protecting at-risk populations.”
The research also supports the role of cellular immunity, specifically CD8+ T cells, in controlling orthopoxvirus infection. Mark Newman, Ph.D., Chief Scientific Officer of GeoVax, noted that the data “point toward an innovative approach to augmenting MVA potency” and support further investigation of a next-generation, single-dose vaccine for orthopoxviruses, with an initial focus on mpox.
MVA-X is part of GeoVax’s broader strategy to expand the utility of the MVA platform. In parallel, the company is advancing continuous cell-line manufacturing and evaluating needle-free microarray patch delivery. These initiatives address dosing, manufacturing, and administration—three critical considerations for vaccine deployment during outbreaks and in global health and biosecurity contexts. GeoVax’s priority program, GEO-MVA, is an MVA-based vaccine targeting mpox and smallpox and is advancing under an expedited regulatory pathway, with plans to initiate a pivotal Phase 3 clinical trial in the second half of 2026.
The preprint is available at bioRxiv. For more information, visit www.geovax.com. The original release is available at www.newmediawire.com. As a preprint, the findings have not been certified by peer review, and results from preclinical animal studies may not predict human outcomes.
