Ebola Virus: An Updated Review on Immunity and Vaccine

Ebola virus (EBOV) is one of the most dangerous viruses in the world which causes fatal hemorrhagic fever syndrome both in humans and nonhuman primates. Major innate immunity mechanisms against EBOV are associated with the production of interferons that are inhibited by viral proteins. Activation of host NK cells was recognized as a leading immune function responsible for recovery of EBOV infected people. Uncontrolled cell infection by EBOV leads to an impairment of immunity. EBOV proteins interaction with host cellular proteins disrupt type I and type II interferon responses, RNAi antiviral responses, antigen presentation, T-cell-dependent B cell responses, humoral immunity, and cell-mediated immunity. These multifaceted approaches to evasion and suppression of innate and adaptive immune responses in their target hosts lead to the severe immune dysregulation and "cytokine storm" that is characteristic of fatal EBOV infection. Long-term control of viral outbreaks requires the use of vaccines to impart acquired resistance and ensuing protection. Development of a safe and efficacious vaccine against EBOV has proven elusive so far, but various inventive strategies are now being employed to counteract the threat of outbreaks caused by EBOV and related filoviruses. This review highlights the host immune responses to EBOV infection, its ability to subvert host immunity and discuss recent advances in prevention of EBOV infection by vaccination.