GeoVax Reports Positive Interim Results for Multi-Antigen COVID-19 Vaccine in Immunocompromised Patients
GeoVax Labs announced promising Phase 2 clinical trial results showing its multi-antigen COVID-19 vaccine candidate demonstrates strong safety and robust T-cell responses in immunocompromised patients, potentially addressing a critical gap in protection for vulnerable populations.
GeoVax Labs, Inc. presented interim results from Phase 2 clinical trials of its multi-antigen COVID-19 vaccine candidate GEO-CM04S1 at the World Vaccine Congress Europe 2025, highlighting favorable safety data and robust immune responses in immunocompromised patient populations. The presentations by senior scientific leadership emphasized the vaccine's potential to address limitations of current COVID-19 vaccines for vulnerable patients who remain at high risk for severe disease.
Chief Scientific Officer Mark J. Newman, PhD, presented data demonstrating that GEO-CM04S1 elicits strong T-cell responses to both Spike and Nucleocapsid antigens, exceeding responses induced by mRNA boosters. The vaccine showed broad, durable immunity in preclinical and early clinical data, including responses against Omicron subvariants. Newman highlighted how the multi-antigen approach could provide longer-lasting protection and reduce the need for frequent vaccine reformulations, addressing the limitations of current "one-size-fits-all" vaccines for immunocompromised populations.
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. While breakthrough infections occurred in some patients, they were mild-to-moderate in severity.
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, with a consistent safety profile emerging across ongoing trials. For more information about the company's clinical programs and technology platform, visit https://www.geovax.com.
GEO-CM04S1 is currently being evaluated in three Phase 2 clinical trials: as a primary vaccine for immunocompromised individuals including post-transplant and hematologic cancer patients, as a booster for patients with chronic lymphocytic leukemia, and as a durable booster for healthy adults previously immunized with mRNA vaccines. The positive interim results suggest the vaccine candidate may offer enhanced protection for populations that have shown inadequate responses to current authorized COVID-19 vaccines, representing a significant advancement in addressing ongoing pandemic challenges for vulnerable patient groups.