GeoVax Labs, Inc. (Nasdaq: GOVX), a clinical-stage biotechnology company developing vaccines and immunotherapies for high-consequence infectious diseases and solid tumor cancers, announced the publication of preclinical research on bioRxiv demonstrating that a single dose of an enhanced Modified Vaccinia Ankara (MVA) vaccine, designated MVA-X, provides durable protection against lethal orthopoxvirus challenges, including highly pathogenic Clade I mpox virus. The findings, which have not yet been peer-reviewed, suggest a potential shift from the conventional two-dose MVA regimen, which could significantly simplify vaccination campaigns during outbreaks.
The research, conducted in collaboration with investigators at Washington State University and funded by GeoVax, showed that a single MVA-X vaccination provided complete protection following lethal and high-dose orthopoxvirus challenge at Days 55, 90, and 150 after vaccination. The single dose achieved protection comparable to a conventional two-dose MVA regimen, restricted viral replication and systemic dissemination, and generated durable antigen-specific CD8+ T-cell responses despite declining circulating antibody levels. Importantly, it also protected highly susceptible animals against lethal challenge with highly pathogenic Clade I mpox virus.
David Dodd, Chairman and CEO of GeoVax, commented, “Two-dose administration has long been an accepted characteristic of MVA vaccination. These results provide encouraging preclinical evidence that it may be possible to achieve durable protection following a single vaccination utilizing MVA-X. The potential significance of such an innovation is considerable. 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.”
Dodd continued, “We also view these findings within a broader effort at GeoVax to expand the utility of MVA as a vaccine platform. We are advancing innovations directed at important considerations in vaccine deployment, including dosing, manufacturing and administration. Our objective is to build upon MVA’s established attributes while developing approaches that could make MVA-based vaccines increasingly practical and deployable for global health, outbreak response and biosecurity.”
Mark Newman, Ph.D., Chief Scientific Officer of GeoVax, added, “These data point toward an innovative approach to augmenting MVA potency and provide support for the important role of the cellular arm of the immune system, particularly CD8-positive T-cell responses, in controlling and clearing orthopoxvirus infection. These findings support further investigation to determine if augmentation of MVA potency can be developed as a next-generation, single-dose vaccine approach for protection against orthopoxvirus infections, with an initial focus on mpox.”
The MVA-X research is part of GeoVax’s broader strategy to enhance 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—key factors that could improve operational flexibility during outbreaks and in resource-constrained settings. GeoVax’s priority program, GEO-MVA, is advancing under an expedited regulatory pathway with plans to initiate a pivotal Phase 3 clinical trial in the second half of 2026. The manuscript is available as a preprint on bioRxiv under DOI 10.64898/2026.07.31.742137. For more information, visit www.geovax.com.
The implications of this announcement are significant for global health and biosecurity. A single-dose MVA vaccine could streamline vaccination efforts, reduce costs, and improve compliance, particularly in areas with limited healthcare infrastructure. If the preclinical results translate to humans, MVA-X could become a critical tool in combating mpox outbreaks and other orthopoxvirus threats. However, as the manuscript is a preprint and has not been peer-reviewed, further clinical testing is necessary to confirm these findings. GeoVax’s ongoing efforts to improve vaccine deployment, including manufacturing and delivery innovations, underscore the company’s commitment to addressing emerging infectious diseases.
