GeoVax Presents Positive Interim COVID-19 Vaccine Data for Immunocompromised Patients at World Vaccine Congress

GeoVax Labs, Inc. announced presentations by its senior scientific leadership at the World Vaccine Congress Europe 2025 highlighting positive interim results for its multi-antigen COVID-19 vaccine candidate GEO-CM04S1 in immunocompromised patients. Chief Scientific Officer Mark J. Newman, PhD presented Phase 2 data demonstrating that GEO-CM04S1 elicits strong T-cell responses to both Spike and Nucleocapsid antigens, exceeding responses induced by mRNA boosters. The presentation highlighted limitations of current one-size-fits-all vaccines for immunocompromised populations and showed GEO-CM04S1's potential to provide broader, more durable protection against COVID-19 variants including Omicron subvariants.

Chief Medical Officer Kelly T. McKee, Jr., MD, MPH presented interim safety results from a Phase 2 trial in patients with hematologic malignancies receiving cellular therapies. The data showed GEO-CM04S1 had a safety profile comparable to mRNA vaccines, with only mild-to-moderate treatment-emergent adverse events predominantly consisting of injection site reactions, fatigue, and myalgia. Importantly, no vaccine-related serious adverse events, myocarditis, or pericarditis have been reported to date. Breakthrough infections occurred but were mild-to-moderate in severity, suggesting the vaccine provides some protection even in this highly vulnerable population.

David Dodd, Chairman and CEO of GeoVax, stated that these data support the company's 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. The MVA-based, multi-antigen approach is designed to provide broader, more durable protection, and the consistent safety profile emerging across ongoing trials is encouraging. GEO-CM04S1 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, and as a durable booster for healthy adults previously immunized with mRNA vaccines.

The implications of these findings are significant for immunocompromised populations who have remained at high risk for severe COVID-19 outcomes despite available vaccines. The robust T-cell responses and favorable safety profile suggest GEO-CM04S1 could provide enhanced protection for patients with hematologic malignancies, transplant recipients, and others with compromised immune systems. The multi-antigen approach targeting both Spike and Nucleocapsid proteins may offer advantages over current vaccines by stimulating broader immune responses and potentially reducing the need for frequent reformulations as new variants emerge. For more information about the company's clinical programs, visit https://www.geovax.com.