Vaccine

No vaccine is currently available for humans. The most promising candidates are DNA vaccines or vaccines derived from adenoviruses, vesicular stomatitis Indiana virus (VSIV) or filovirus like particles (VLPs) because these candidates could protect nonhuman primates from ebolavirus induced disease. DNA vaccines, adenovirus based vaccines, and VSIV based vaccines have entered clinical trials. Vaccines have protected nonhuman primates. Immunization takes six months, which impedes the counter epidemic use of the vaccines. Searching for a quicker onset of effectiveness, in 2003 a vaccine using an adenoviral (ADV) vector carrying the Ebola spike protein was tested on crab eating macaques. Twenty eight days later they were challenged with the virus and remained resistant. A vaccine based on attenuated recombinant vesicular stomatitis virus (VSV) vector carrying either the Ebola glycoprotein or the Marburg glycoprotein in 2005 protected nonhuman primates, opening clinical trials in humans.The study by October completed the first human trial, over three months giving three vaccinations safely inducing an immune response. Individuals for a year were followed, and, in 2006, a study testing a faster acting, single shot vaccine began; this new study was completed in 2008. Trying the vaccine on a strain of Ebola that more resembles one that infects humans is the next step.