GeoVax's Multi-Antigen COVID-19 Vaccine Shows Strong Immune Response in Immunocompromised Patients

GeoVax Labs, Inc. presented positive interim clinical results for its lead COVID-19 vaccine candidate, GEO-CM04S1, at the 6th European Society of Clinical Microbiology and Infectious Disease Conference on Vaccines in Lisbon, Portugal. The data highlighted encouraging immune response findings from ongoing Phase 2 clinical studies in immunocompromised patients with blood cancers and chronic lymphocytic leukemia.

The clinical results showed no serious adverse events attributed to GEO-CM04S1, reinforcing confidence in the platform. The vaccine demonstrated potent, durable T-cell and cross-variant antibody responses in blood cancer and post-transplant patients, with immune responses that exceed those of standard-of-care vaccines. In the chronic lymphocytic leukemia trial interim analysis, GEO-CM04S1 met its primary endpoint while the comparator mRNA vaccine did not, prompting continuation solely in the GEO-CM04S1 arm.

GEO-CM04S1 is a next-generation COVID-19 vaccine based on a Modified Vaccinia Ankara vector that expresses both the Spike and Nucleocapsid proteins of SARS-CoV-2, designed to stimulate robust humoral and cellular immunity. Clinical studies to date demonstrate durable immune responses and cross-variant protection, including activity against Omicron subvariants such as XBB.1.5. An updated construct incorporating the Omicron KP.2 Spike gene is expected to begin clinical testing in 2026, positioning GeoVax at the forefront of next-generation, multi-antigen COVID-19 vaccines.

COVID-19 continues to pose a significant threat to immunocompromised patients, representing a multi-billion-dollar global market where first-generation vaccines have limited value. GEO-CM04S1's multi-antigen approach positions GeoVax to lead in this underserved space while providing platform validation for broader applications across infectious diseases. The company maintains a strong intellectual property portfolio in support of its technologies and product candidates, holding worldwide rights for its technologies and products. For more information, visit https://www.geovax.com.