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GeoVax Comments on Recent Paper Addressing Safety Concerns Over Ebola Vaccines Under Development
Design of GeoVax Ebola Vaccine Expected to Overcome Potential Safety Issues
ATLANTA, GA, August 23, 2018 – GeoVax Labs, Inc. (OTCQB: GOVX), a biotechnology company developing human vaccines, today commented on a paper published by Iampietro et al, from the Department of Pathology, University of Texas Medical Branch at Galveston, Texas, in The Journal of Infectious Diseases, concerning new findings on how the Ebola virus (EBOV) disables the host immune system and spreads infection.
In the article, “Ebola Virus Shed Glycoprotein Triggers Differentiation, Infection, and Death of Monocytes Through Toll-Like Receptor 4 Activation”, the authors conclude that the very high levels of EBOV glycoprotein (GP) shed by EBOV and live Ebola vaccines may play a role in pathogenesis and associated vaccine-related adverse effects (e.g. oligoarthritis, maculopapular dermatitis, vesicular dermatitis, and dermal vasculitis)1.
Farshad Guirakhoo, PhD, GeoVax’s Chief Scientific Officer, commented, “This could be an important safety issue that requires post-marketing surveillance when certain vaccines under development are potentially administered in millions of doses, especially in countries across sub-Saharan Africa where widespread HIV infection can compromise the immune systems of people being vaccinated. The Ebola vaccine constructs used in this in vitro study (human parainfluenza type 3, HPIV3 and vesicular stomatitis virus, VSV) are chimeric viruses made in the laboratory by swapping the GP genes of the vectors with the GP genes of the vaccine viruses. These chimeras replicate very efficiently in their vaccinated hosts.”
Dr. Guirakhoo continued, “In contrast to live vaccines, all of the GeoVax vaccine candidates (e.g. Ebola, Lassa, Marburg, Sudan, Zika, etc.) are not considered chimeric (not swapping the GP genes), are replication-deficient in mammalian hosts, and therefore are not capable of undergoing multiple rounds of replication necessary to produce high amounts of shed GP in the circulation of vaccinees. But based on the findings of this study, we are planning to test our vaccines to assure that the GP production does not induce death of monocytes. Despite the replication deficiency of our vaccines in humans, they offer full protection, similar to replicating vectors, without compromising the safety (e.g. adverse events)2 after a single dose. Another unique benefit of our vaccines is that we use two antigens for construction of VLPs which not only enhances the immunogenicity of the vaccine but could also broaden the immune response to protect against more viral strains.”
GeoVax’s vaccine technology is based on its Modified Vaccinia Ankara (MVA) Virus-Like Particle (VLP) platform, which generates noninfectious VLPs in the individual being vaccinated. Gene sequences of target antigens are inserted into the MVA genome which drives their expression in infected cells. In addition, GeoVax introduces into the viral genome matrix sequences that incorporate antigens into VLPs and simultaneously facilitate their budding from the membranes of host cells. In this way, vaccination induces two pools of antigens as targets for the immune response – host cells and VLPs secreted from host cells. This strategy mimics a natural viral infection, triggering the body to produce a robust and durable immune response with involvement of both antibodies and T cells.
GeoVax Labs, Inc., is a clinical-stage biotechnology company developing human vaccines against infectious diseases using its MVA-VLP vaccine platform. GeoVax was the winner of the 2018 “Best Biotech” Vaccine Industry Excellence Awards, a finalist for the 2018 “Best Prophylactic Vaccine” Award for its Zika vaccine at the World Vaccine Congress, as well as a finalist for Pipelines of Promise at Buzz of Bio 2018. The Company’s development programs are focused on vaccines against HIV, Zika, hemorrhagic fever viruses (Ebola, Sudan, Marburg, Lassa) and malaria. GeoVax also is evaluating the use of its MVA-VLP platform in cancer immunotherapy, and for therapeutic use in chronic Hepatitis B infections. GeoVax’s vaccine platform supports in vivo production of non-infectious VLPs from the cells of the very person receiving the vaccine. The production of VLPs in the person being vaccinated mimics virus production in a natural infection, stimulating both the humoral and cellular arms of the immune system to recognize, prevent, and control the target infection. For more information, visit www.geovax.com.
Certain statements in this document are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act. These statements are based on management's current expectations and are subject to uncertainty and changes in circumstances. Actual results may differ materially from those included in these statements due to a variety of factors, including whether: GeoVax can develop and manufacture its vaccines with the desired characteristics in a timely manner, GeoVax's vaccines will be safe for human use, GeoVax's vaccines will effectively prevent targeted infections in humans, GeoVax’s vaccines will receive regulatory approvals necessary to be licensed and marketed, GeoVax raises required capital to complete vaccine 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. GeoVax assumes no obligation to update these forward-looking statements. More information about these factors is contained in GeoVax's filings with the Securities and Exchange Commission including those under "Risk Factors" in its Form 10-K.
1. Huttner A, Dayer JA, Yerly S, et al. The effect of dose on the safety and immunogenicity of the VSV Ebola candidate vaccine: a randomised double-blind, placebo-controlled phase 1/2 trial. Lancet Infect Dis. 2015 Oct;15(10):1156-1166. doi: 10.1016/S1473-3099(15)00154-1. Epub 2015 Aug 4.
2. Goepfert PA, Elizaga ML, Seaton K, et al. Specificity and 6-month durability of immune responses induced by DNA and recombinant modified vaccinia Ankara vaccines expressing HIV-1 virus-like particles. J Infect Dis. 2014 Jul 1;210(1):99-110. doi: 10.1093/infdis/jiu003. Epub 2014 Jan 7.