Ebola virus vaccines: an overview of current approaches

Abstract

Ebola hemorrhagic fever is one of the most fatal viral diseases worldwide affecting humans and nonhuman primates. Although infections only occur frequently in Central Africa, the virus has the potential to spread globally and is classified as a category A pathogen that could be misused as a bioterrorism agent. As of today there is no vaccine or treatment licensed to counteract Ebola virus infections. DNA, subunit and several viral vector approaches, replicating and non-replicating, have been tested as potential vaccine platforms and their protective efficacy has been evaluated in nonhuman primate models for Ebola virus infections, which closely resemble disease progression in humans. Though these vaccine platforms seem to confer protection through different mechanisms, several of them are efficacious against lethal disease in nonhuman primates attesting that vaccination against Ebola virus infections is feasible.

Figure 1. Ebola hemorrhagic fever outbreaks in Africa since discovery in 1976

Maps depicting documented outbreaks of Ebola hemorrhagic fever in Africa for the last five decades. 1970s – five documented outbreaks; 1980s – no reported outbreaks; 1990s – six confirmed outbreaks; 2000s – 10 documented outbreaks; 2010s – so far five confirmed outbreaks. BEBOV: Bundibugyo ebolavirus; SEBOV: Sudan ebolavirus; TFEBOV: Taï forest ebolavirus; X: outbreak location; ZEBOV: Zaire ebolavirus.