Ebola virus: an updated review on immunity and vaccine

Ebola virus (EBOV) derived its name from the Ebola River in Democratic Republic of Congo (DRC) (formerly Zaire) where the first Ebola virus disease (EVD) outbreak was observed in 1976 [1]. EBOV is enveloped, non-segmented, negative-stranded RNA virus containing filamentous virion which belongs to the family Filoviridae. EVD is caused by filamentous EBOV associated with mortality rates between 25 and 90 % [2]. The clinical symptoms of this disease are non-specific and flu-like, such as high fever, headache and myalgia at the early stage [3]. The symptoms also included diarrhea and vomiting when the large outbreak occurs in West Africa (2014 to present) [4]. Immune cell disorders are associated at the late stage of this disease such as, diffuse intravascular coagulopathy caused by coagulation and neutrophilia disorders [5-7]. Humans may acquire the disease by close contact with biological fluids of the infected animals or patients. During the acute phase of illness, EBOV has been detected in different body fluids including breast milk, saliva, semen, stool, sweat, tears and urine [8-12]. EBOV has been isolated from urine (9 days) and from aqueous humor (9 weeks) after the virus was cleared from plasma [13].