• Vaccine Name: DNA vaccine expressing sGP
• Target Pathogen: Ebola virus
• Target Disease: Ebola hemorrhagic fever
• Vaccine Ontology ID: VO_0000785
• Type: DNA vaccine
• GP from Reston ebolavirus gene engineering:
  • Type: DNA vaccine construction
  • Description:
  • Detailed Gene Information: Click Here.
• DNA vaccine plasmid:
  • DNA vaccine plasmid name:
  • DNA vaccine plasmid VO ID: VO_0000215
• Preparation: Plasmids containing the sGP cDNAs are used to subclone the relevant inserts into CMV expression vectors, which utilize the bovine growth hormone polyadenylation sequence. The plasmid pCRII-sGP is digested with EcoRI and treated with Klenow enzyme, and the resulting fragment is inserted into the BamHI/Bg/II CMV plasmid, which has been incubated with Klenow fragment and calf intestinal phosphate (CIP), and phenol chloroform extracted (Xu et al., 1998).
• Description: sGP is a secreted or transmembrane form of glycoprotein (Xu et al., 1998).

Guinea pig Response

• Vaccination Protocol: Two groups of guinea pigs were immunized by injection of 0.5 mg/ml in each hind leg (two injections at each time point) with the plasmed expression vectors. Animals were challenged by inoculation with a stock of Ebola virus that had been passaged once in Vero E6 cells and serially passaged by intraperitoneal injection of slpeen homogenates in Hartley guinea pigs seven times. Immunized guinea pigs were injected intraperitoneally with 0.5 ml of a 1:1000 dillution of spleen cell homogenate in Hanks' balanced salt solution 122 days after the initial plasmid DNA injection. Survival was determined 10 days later at which times animals were killed for serologic and pathologic analysis (Xu et al., 1998).
• Persistence: None noted
• Immune Response: A broad immune response was conferred by sGP which induced both cellular and humoral immunity to the membrane-associated GP. The ability of vectors expressing GP to confer immunity may be explained by the generation of the lower molecular weight degradation products, which could provide sufficient protein for antigen presentation to induce detectable, cellular and humoral immune responses in guinea pigs (Xu et al., 1998).
• Side Effects: None noted
• Efficacy: For the first group of 6 giunea pigs, animals were challenged within 2 months after the initial immunization. Five of six of the immunized subjects survived in contrast to 0/6 control subjects. In the second group, guinea pigs were challenged 4 months after the initial immunization. Three of the five guinea pigs immunized with sGP showed no ill effects following the viral challenge (Xu et al., 1998).