Malaria is a mosquito-borne disease caused by Plasmodium parasites. Symptoms are fever, chills, sweating, vomiting and flu-like illness. If untreated, severe complications (severe anemia, cerebral malaria and organ failure) will lead to death. Over 3 billion people in 106 countries and territories live at risk of malaria infection. According to the latest estimates from the World Health Organization (WHO), 214 million new cases of malaria were recorded worldwide in 2015, resulting in 438,000 deaths. There are 1,500 cases in the US each year (travelers returning home). Children under five years of age are particularly susceptible to malaria illness, infection, and death. In 2015, malaria killed an estimated 306,000 children. Current treatments include bed net distributions, drug treatment and mosquito spraying. Malaria parasite develop resistance to drugs and insecticides. Even though vaccines have shown to be the most cost-effective ways to fight and eliminate infectious diseases (smallpox, polio, etc.), and many decades of research and development, there is no commercial malaria vaccine at the present time. Even a vaccine with efficacy of 30-50% will prevent hundreds of thousands of deaths annually. Current vaccine candidates are generally consisting of subunit proteins, are poorly immunogenic, based on limited number of antigens (4-5), do not target multi-stages of parasite life cycle, and do not induce strong durable functional antibodies and T cell responses. Therefore, identification of appropriate antigens and vaccine technologies is critical for development of an effective malaria vaccine.
GeoVax Malaria Approach
An ideal malaria vaccine candidate should contain antigens from multiple stages of malaria life cycle, should induce functional antibodies (predominantly IgG1 and IgG3 subtypes shown to be associated with protection) and strong cell mediated immunity (e.g. Th1 biased CD4+ ad CD8+) to reduce parasitemia by clearing infected cells (liver cells or erythrocytes)). We have shown (in animal models and humans) that MVA-VLP vaccines induce a Th1 biased response with both durable functional antibodies (IgG1 and IgG3) and CD4+ and CD8+ T cell responses both of which are hallmarks of an ideal malaria vaccine.
GeoVax has established a collaboration agreement with the Burnet Institute, a leading infectious diseases research institute in Australia, for the development of a vaccine to prevent malaria infection (Press Release). The project will include the design, construction, and characterization of multiple malaria vaccine candidates using GeoVax’s MVA-VLP vaccine platform combined with malaria Plasmodium falciparum and Plasmodium vivax sequences identified by the Burnet Institute. The vaccine design, construction, and characterization were performed at GeoVax with further characterization and immunogenicity studies in mice and rabbits conducted at Burnet Institute using their unique functional assays that provide key information on vaccine efficacy.