Vaccines and antivirals for filoviruses

For more than 35 years the filoviruses, Ebola virus and Marburg virus, have caused sporadic outbreaks of hemorrhagic fever resulting in severe and often fatal disease in humans and nonhuman primates. Pathogenic Ebola and Marburg viruses are endemic in resource-poor regions in Central and West Africa and are also of concern as they have the potential for deliberate misuse as bioweapons. Although no vaccines or antivirals for filoviruses are currently licensed for human use, remarkable progress has been made in developing candidate preventive vaccines and antivirals against Ebola and Marburg viruses in nonhuman primate models. Two efficacious non-replicating vaccines tested in nonhuman primates consist of DNA or virus-like particles, while most of the effective vaccines are based on viral vectors including: recombinant adenoviruses, alphaviruses, paramyxoviruses, and rhabdoviruses. Successful post-exposure treatments against filoviruses to date consist of recombinant vesicular stomatitis virus vaccine vectors, antibody cocktail treatments, targeting virus genes or genomes through RNA interference, and use of a nucleoside analogue. While these vaccines and antivirals have shown great promise in nonhuman primate models, there are questions that remain in regard to providing broad-spectrum immunity and/or treatments for the different species of Ebola and strains of Marburg viruses.