GeoVax’s Next-Generation COVID-19 Vaccine Shows High Immunogenicity in Immunocompromised Patients

Atlanta, GA, May 24, 2023 – GeoVax Labs, Inc. (Nasdaq: GOVX), a biotechnology company developing immunotherapies and vaccines against cancers and infectious diseases, announced today the presentation of updates on the development of its next-generation SARS-CoV-2 vaccine, GEO-CM04S1, including preliminary data from an ongoing Phase 2 clinical trial, during the Vaccines Summit Boston 2023 and the Congress for the International Society for the Advancement of Cytometry (CYTO) 2023 meetings.

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Each of the presentations included unpublished data from the open-label portion of the Phase 2 trial of CM04S1 (ClinicalTrials.gov Identifier: NCT04977024 ) in patients undergoing hematological cancer treatment (i.e., patients who have reduced immune system function as a result of treatment ). The preliminary analysis indicated CM04S1 is highly immunogenic in these patients, inducing both antibody responses, including neutralizing antibodies as well as T cell responses. These data support the planned progression of the Phase 2 clinical study, which includes a direct comparison to currently approved mRNA vaccines.

Kelly McKee, M.D., GeoVax’s Chief Medical Officer, commented, “These data extend to severely immunocompromised patients our earlier findings in healthy adults that GEO-CM04S1 stimulated a robust, durable, and broad-based humoral and cellular immune response against multiple SARS-CoV-2 variants. Validation of these findings in additional patients with hematologic malignancies, who have received CAR-T and stem cell transplants, is underway as we seek to provide a vaccine solution to those individuals unable to mount adequate protective responses with currently available COVID-19 vaccines.”

CM04S1 continues to advance in a second Phase 2 clinical trial as a booster for healthy patients who have previously received the Pfizer or Moderna mRNA vaccine (ClinicalTrials.gov Identifier: NCT04639466 ). Data from these studies will form the basis for comparing vaccine potential in unique patient groups as well as the general population.

About GEO-CM04S1

CM04S1 is a next-generation COVID-19 vaccine based on GeoVax’s MVA viral vector platform, which supports the presentation of multiple vaccine antigens to the immune system in a single dose. CM04S1 presents both the spike and nucleocapsid antigens of SARS-CoV-2 and is specifically designed to induce both antibody and T cell responses to non-variable parts of the virus. The more broadly specific and functional engagement of the immune system is designed to provide protection against the new and continually emerging variants of COVID-19. Based on data from animal models and a completed Phase 1 clinical study, vaccine-induced immune responses were shown to recognize both early and later variants of SARS-CoV-2, including the Omicron variant. Vaccines of this format should not require repeated modification and updating.

CM04S1 continues to advance in two Phase 2 clinical studies, one as a primary vaccine for immunocompromised cancer patients, in direct comparison to either the Pfizer or Moderna mRNA vaccine (ClinicalTrials.gov Identifier: NCT04977024 ), and the second as a booster for healthy patients who have previously received either the Pfizer or Moderna vaccine as their initial inoculation (ClinicalTrials.gov Identifier: NCT04639466 ).  

About GeoVax

GeoVax Labs, Inc. is a clinical-stage biotechnology company developing novel therapies and vaccines for solid tumor cancers and many of the world’s most threatening infectious diseases. The company’s lead program in oncology is a novel oncolytic solid tumor gene-directed therapy, Gedeptin ® , presently in a multicenter Phase 1/2 clinical trial for advanced head and neck cancers. GeoVax’s lead infectious disease candidate is GEO-CM04S1, a next-generation COVID-19 vaccine targeting high-risk immunocompromised patient populations. Currently in two Phase 2 clinical trials, GEO-CM04S1 is being evaluated as a COVID-19 vaccine for immunocompromised patients such as those suffering from hematologic cancers and other patient populations for whom the current authorized COVID-19 vaccines are insufficient. In addition, GEO-CM04S1 is in a Phase 2 clinical trial evaluating the vaccine as a more robust, durable COVID-19 booster among healthy patients who previously received the mRNA vaccines. GeoVax has a leadership team who have driven significant value creation across multiple life science companies over the past several decades. For more information, visit our website: www.geovax.com.

September 11, 2025
Members are invited to join G2G’s Monthly GBG Reporting Service Webinar on September 18, 2025 . The first portion ( 12:00–12:30 PM ET ) is free and open to all, offering a high-level overview of current federal funding trends. The second half ( 12:30–1:00 PM ET ) is a premium consultation available only to Georgia Life Sciences members, offering direct access to G2G’s expert team—who have helped secure over $550 million in non-dilutive government funding since 2007. Register here: https://www.g2gconsulting.com/event/non-dilutive-funding-g2gs-monthly-gbg-reporting-service-webinar-14-3/2025-09-18/ Key opportunities this month include DARPA’s Expedited Research Innovation System for CBRN threat defense technologies, BARDA’s I-CREATE diagnostic funding and VANGUARD biomanufacturing tools development (each offering up to $200,000), NIAID tuberculosis and influenza research units (up to $1.5–$2.5 million annually), DoD’s $4 million Advanced Medical Monitor development through MTEC, and multiple SBIR opportunities for sensors and field-deployable diagnostics (up to $209,575 for Phase I awards). The September GBG report highlights 13 immunology and infectious disease opportunities, 10 cognitive and brain health programs, and several biotechnology and biomanufacturing initiatives across federal agencies including the Army, ARPA-H, BARDA, and NSF. Georgia Life Sciences members can access the complete 29-page report with detailed deadlines and eligibility requirements [insert link or portal instructions here]. GLS members can access the full 29-page report with deadlines and submission details by logging into your member portal.
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