GeoVax Labs, Inc. announced the presentation of preclinical vaccine efficacy data for GEO-CM02, a multi-antigen investigational SARS-CoV-2 vaccine. The data were presented during the Vaccines Summit 2023 conference, being held in Boston, MA on November 13-15, 2023. The presentation, titled ?MVA-vectored multi-antigen COVID-19 vaccines induce protective immunity against SARS-CoV-2 variants spanning Alpha to Omicron in preclinical animal models,?

was delivered by Mukesh Kumar, PhD, Associate Professor, Department of Biology, Georgia State University. First-generation SARS-CoV-2 vaccines based on the spike (S) protein have demonstrated that they induce neutralizing antibodies, providing effective, albeit short-term levels of immune protection. Unfortunately, with the existing authorized vaccines, efficacy is disrupted by emerging variants that contribute to neutralizing antibody evasion, requiring continuous updating and booster doses. To address this limitation, GeoVax is currently evaluating its dual antigen COVID-19 vaccine, GEO-CM04S1 in three Phase 2 clinical trials.  GEO-CM04S1 encodes for both the spike (S) and nucleocapsid (N) antigens of SARS-CoV-2 and is specifically designed to induce both antibody and T cell responses to those parts of the virus less likely to mutate over time.

The more broadly functional engagement of the immune system is designed to protect against severe disease caused by continually emerging variants of COVID-19. Vaccines of this format should not require frequent and repeated modification or updating. Moreover, GEO-CM04S1 is being developed specifically as a COVID-19 vaccine in support of patients with compromised immune systems, for whom the current authorized vaccines appear inadequate in providing protective immunity.

GEO-CM02 is a multi-antigen SARS-CoV-2 vaccine, based on the S, membrane (M), and envelope (E) proteins, which are designed to also engage both the humoral (antibody) and cellular (T-cell) arms of the immune system and to broaden both the function and specificity, potentially as a universal coronavirus vaccine. Efficacy of this investigational vaccine was tested using the industry standard, lethal hACE2 transgenic mouse model. Data highlights from the Vaccine Summit 2023 presentation are as follows: The GEO-CM02 vaccine induced immune responses that were efficacious against the original Wuhan strain and BA.1 Omicron variant with a single dose.

Animals were protected prior to the detection of neutralizing antibodies, likely indicating a critical T-cell contribution. GEO-CM02 significantly reduced or eliminated inflammation and immunopathology in the lungs of vaccinated animals. The data generated in the GEO-CM02 studies validate GeoVax?s hypothesis that vaccines designed to induce both antibodies and T-cells to multiple viral structural proteins can address the issue of viral variation and escape from the immune system.

GEO-CM02 is based on GeoVax?s MVA viral vector platform, which supports the presentation of multiple vaccine antigens to the immune system in a single dose. GeoVax?s more advanced, next-generation COVID-19 vaccine, GEO-CM04S1, is being evaluated in three ongoing Phase 2 clinical trials: As a primary vaccine in immunocompromised patients (with hematologic cancers receiving cell transplants or CAR-T therapy). ClinicalTrials.gov Identifier: NCT04977024.

GeoVax recently announced clinical site expansion for this trial. As a booster vaccine in immunocompromised patients with chronic lymphocytic leukemia (CLL), a recognized high-risk group for whom current mRNA vaccines and monoclonal antibody (MAb) therapies appear inadequate relative to providing protective immunity. ClinicalTrials.gov Identifier: NCT05672355.

As a booster vaccine for healthy patients who have previously received the Pfizer or Moderna mRNA vaccine. ClinicalTrials.gov Identifier: NCT04639466. GeoVax recently announced that this trial has fully enrolled.