Preclinical Studies Demonstrate Durable Protection Against SARS-CoV-2 Variants, Including Omicron XBB.1.5, Driven by T-Cell Responses
ATLANTA, GA - June 9, 2025 (NEWMEDIAWIRE) - GeoVax Labs, Inc. (Nasdaq: GOVX), a clinical-stage biotechnology company developing immunotherapies and multi-antigen vaccines against infectious diseases and solid tumors, today recapped two scientific poster presentations delivered at the Keystone Symposia on Vaccinology: Horizons Across Disease, Demography and Technology, held June 47, 2025, in Washington, D.C.
The presentations, titled MVA-Vectored Multi-Antigen COVID-19 Vaccines Induce Protective Immunity Against SARS-CoV-2 Variants Spanning Alpha to Omicron in Preclinical Animal Models, and GEO-CM04S1 Vaccine Candidate Maintains Potent Cross-Reactivity Against Original SARS-CoV-2 B.1 and Omicron Subvariant XBB.1.5, were delivered by Drs. Pratima Kumari and Amany Elsharkawy, respectively, members of GeoVax's scientific team and its collaborators, during the June 5 and June 6 poster sessions. The presentations spotlight the Company's Modified Vaccinia Ankara (MVA)-vectored COVID-19 vaccine candidates, GEO-CM04S1 and GEO-CM02, and their ability to induce durable, cross-reactive immunity against SARS-CoV-2 variants in preclinical animal models. These studies underscore the immunologic breadth, durability, and cross-variant protection of GeoVax's multi-antigen design strategy, especially important for addressing variant evasion and suboptimal immune response in vulnerable patient populations.
Key Findings from Studies
GEO-CM02 Study Poster #1050 - Presenter: Dr. Pratima Kumari, GeoVax Scientist
This presentation detailed findings for GEO-CM02, a multi-antigen MVA-based vaccine expressing the spike (S), membrane (M), and envelope (E) proteins.
In hACE2 mouse models, a single dose provided complete protection against both the original Wuhan strain and the Omicron BA.1 variant.
Two-dose regimens generated high neutralizing antibody levels, reduced viral loads in lung and brain tissues, and lowered inflammatory markers- indicating enhanced immune memory.
Notably, early protection was achieved prior to detectable neutralizing antibodies, further supporting the role of innate and cellular immune responses in viral control. This underscores the value of the multi-antigen MVA-based vaccine platform, particularly as the virus continues to mutate.
GEO-CM04S1 Study Poster #2047 - Presenter: Dr. Amany Elsharkawy, Georgia State University Scientist
This study evaluated the immunogenicity and protective efficacy of GEO-CM04S1, an MVA-vectored vaccine co-expressing spike (S) and nucleocapsid (N) proteins, in a K18-hACE2 mouse model. Mice were challenged intranasally with either the original B.1 strain or the Omicron XBB.1.5 subvariant.
GEO-CM04S1 conferred full protection against clinical disease, lung injury, and inflammation in both viral challenge models.
Despite the absence of detectable neutralizing antibodies against XBB.1.5, vaccinated animals were fully protected, suggesting antibody-independent protection.
Immune cell depletion studies revealed that CD4+ T cells, not B cells or CD8+ T cells, were critical for protection, highlighting the vaccine's ability to drive T cellmediated immunity across variants.
"These experimental findings document the value of inducing broadly specific immune responses to protect against evolving SARS-CoV-2 variants," said Mark Newman, PhD, Chief Scientific Officer of GeoVax. "We believe the use of multi-antigen vaccines could provide significant benefit by limiting the need to continually update COVID vaccines and by limiting the need for yearly booster doses."
GeoVax's MVA vaccine platform is designed to address gaps in pandemic preparedness and public health resilience, with lead vaccine candidate GEO-CM04S1 currently being evaluated in multiple Phase 2 clinical trials for COVID-19.
About GEO-CM04S1
GEO-CM04S1 is a synthetic next-generation, multi-antigen MVA-vectored COVID-19 vaccine co-expressing spike (S) and nucleocapsid (N) antigens, designed to induce both broad antibody and T-cell responses. It is being evaluated in three ongoing Phase 2 clinical trials:
A primary vaccine for immunocompromised individuals (e.g., post-transplant, CAR-T, or hematologic cancers)
A booster for patients with chronic lymphocytic leukemia (CLL)
A booster for healthy adults previously immunized with mRNA vaccines
About GeoVax
GeoVax Labs, Inc. is a clinical-stage biotechnology company developing novel vaccines against infectious diseases and therapies for solid tumor cancers. The Company's lead clinical program is GEO-CM04S1, a next-generation COVID-19 vaccine currently in three Phase 2 clinical trials, being evaluated as (1) a primary 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, (2) a booster vaccine in patients with chronic lymphocytic leukemia (CLL) and (3) a more robust, durable COVID-19 booster among healthy patients who previously received the mRNA vaccines. In oncology the lead clinical program is evaluating a novel oncolytic solid tumor gene-directed therapy, Gedeptin(R), having recently completed a multicenter Phase 1/2 clinical trial for advanced head and neck cancers. The Company is also developing GEO-MVA, a vaccine targeting Mpox and smallpox. GeoVax has a strong IP portfolio in support of its technologies and product candidates, holding worldwide rights for its technologies and products. For more information about the current status of our clinical trials and other updates, visit our website: www.geovax.com.
Forward-Looking Statements
This release contains forward-looking statements regarding GeoVax's business plans. The words "believe," "look forward to," "may," "estimate," "continue," "anticipate," "intend," "should," "plan," "could," "target," "potential," "is likely," "will," "expect" and similar expressions, as they relate to us, are intended to identify forward-looking statements. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends that we believe may affect our financial condition, results of operations, business strategy and financial needs. Actual results may differ materially from those included in these statements due to a variety of factors, including whether: GeoVax is able to obtain acceptable results from ongoing or future clinical trials of its investigational products, GeoVax's immuno-oncology products and preventative vaccines can provoke the desired responses, and those products or vaccines can be used effectively, GeoVax's viral vector technology adequately amplifies immune responses to cancer antigens, GeoVax can develop and manufacture its immuno-oncology products and preventative vaccines with the desired characteristics in a timely manner, GeoVax's immuno-oncology products and preventative vaccines will be safe for human use, GeoVax's vaccines will effectively prevent targeted infections in humans, GeoVax's immuno-oncology products and preventative vaccines will receive regulatory approvals necessary to be licensed and marketed, GeoVax raises required capital to complete development, there is development of competitive products that may be more effective or easier to use than GeoVax's products, GeoVax will be able to enter into favorable manufacturing and distribution agreements, and other factors, over which GeoVax has no control.
Further information on our risk factors is contained in our periodic reports on Form 10-Q and Form 10-K that we have filed and will file with the SEC. Any forward-looking statement made by us herein speaks only as of the date on which it is made. Factors or events that could cause our actual results to differ may emerge from time to time, and it is not possible for us to predict all of them. We undertake no obligation to publicly update any forward-looking statement, whether as a result of new information, future developments or otherwise, except as may be required by law.
