GeoVax Labs, Inc. (Nasdaq: GOVX) presented positive interim results for its multi-antigen COVID-19 vaccine candidate GEO-CM04S1 at the World Vaccine Congress Europe 2025, held October 13-16 in Amsterdam. The presentations highlighted the vaccine's potential to provide broader and more durable protection for immunocompromised patients, who often respond poorly to existing vaccines.
Dr. Mark J. Newman, Chief Scientific Officer, delivered a workshop presentation emphasizing the limitations of current "one-size-fits-all" vaccines for immunocompromised populations. He presented Phase 2 data showing that GEO-CM04S1 elicits strong T-cell responses to both Spike (S) and Nucleocapsid (N) antigens, exceeding responses induced by mRNA boosters. The vaccine demonstrated broad, durable immunity in preclinical and early clinical data, including responses against Omicron subvariants. This suggests GEO-CM04S1 could provide longer-lasting protection and reduce the need for frequent reformulations.
Dr. Kelly T. McKee, Jr., Chief Medical Officer, presented interim safety results from a Phase 2 trial in patients with hematologic malignancies who received hematopoietic stem cell transplants or CAR-T cell therapy. The study reported that GEO-CM04S1 showed a safety profile comparable to mRNA vaccines, with only mild-to-moderate adverse events such as injection site reactions, fatigue, and myalgia. No vaccine-related serious adverse events, myocarditis, or pericarditis have been reported. Breakthrough infections were mild-to-moderate in severity.
David Dodd, Chairman & CEO of GeoVax, stated, "These data continue to support our conviction that GEO-CM04S1 has the potential to fill a critical gap for immunocompromised patients who are not adequately protected against severe COVID-19 by existing vaccines. Our MVA-based, multi-antigen approach is designed to provide broader, more durable protection, and we are encouraged by the consistent safety profile emerging across the ongoing trials."
GEO-CM04S1 is a next-generation COVID-19 vaccine candidate that co-expresses spike and nucleocapsid antigens using GeoVax's MVA vector platform. It is being evaluated in three Phase 2 clinical trials: as a primary vaccine for immunocompromised individuals, as a booster for patients with chronic lymphocytic leukemia (CLL), and as a durable booster for healthy adults previously immunized with mRNA vaccines. For more information, visit www.geovax.com.
