GeoVax Labs, Inc. (Nasdaq: GOVX) announced on September 21, 2026, 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 could have significant implications for vaccine deployment during outbreaks and for global health preparedness.
The manuscript, titled “Single-dose Efficacy of a Next-Generation Mpox Vaccine Harnessing an Immunomodulatory Peptide,” reports that a single administration of MVA-X achieved protection comparable to a conventional two-dose MVA regimen across multiple challenge models. Importantly, the single dose protected highly susceptible animals against lethal Clade I mpox virus at Days 55, 90, and 150 post-vaccination. The research was conducted in collaboration with Washington State University and funded by GeoVax. The preprint is available at bioRxiv.
Current MVA-based mpox vaccines typically require a two-dose regimen. Reducing that to a single dose could simplify deployment, accelerate vaccination programs, and reduce logistical burdens during outbreaks, according to David Dodd, Chairman and CEO of GeoVax. “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 said.
The study also showed that MVA-X generated durable antigen-specific CD8+ T-cell responses even as circulating antibody levels declined, suggesting that enhancing early immune priming may be key to durable single-dose protection. Mark Newman, Ph.D., Chief Scientific Officer of GeoVax, noted that the data support the important role of cellular immunity, particularly CD8+ T cells, in controlling 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,” Newman said.
The MVA-X research 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, especially in resource-constrained or biosecurity settings. The company’s lead program, GEO-MVA, is advancing under an expedited regulatory pathway with plans to initiate a pivotal Phase 3 trial in the second half of 2026.
While the findings are preclinical and may not predict human results, they provide encouraging evidence that a single-dose MVA vaccine could be feasible. If validated in clinical trials, such a vaccine could significantly enhance outbreak response capabilities and global health security by making vaccination campaigns faster and easier to implement. GeoVax maintains a global intellectual property portfolio supporting its infectious disease and oncology programs. For more information, visit www.geovax.com.
