• Vaccine Name: GP-VRP
• Target Pathogen: Ebola virus
• Target Disease: Ebola hemorrhagic fever
• Vaccine Ontology ID: VO_0000780
• Type: Recombinant vector vaccine
• GP from Reston ebolavirus gene engineering:
  • Type: Protein
  • Description:
  • Detailed Gene Information: Click Here.
• Preparation: The Ebola GP genes from the Mayinga strain of Ebola virus were derived from pGEM3Zf(-)-based plasmid. The BamHI±KpnI (2.4 kb) fragment containing the GP gene was subcloned into a shuttle vector. From the shuttle vector, GP gene was transferred as ClaI-fragment into the ClaI site of the replicon clone, resulting in plasmids encoding the GP gene in place of the VEE structural protein genes (Pushko et al., 2000).
• Virulence:

Mouse Response

• Host Strain: BALB/c
• Vaccination Protocol: VRP were diluted in PBS and administered to 6±8 week old BALB/c mice. Groups of 10 BALB/c mice were inoculated on days 0 and 28 with two doses of NP-VRP, GP-VRP, or a mixture of both. Challenge was carried out 4 weeks after final immunization with VRP. Mice were challenged i.p. with mouse-adapted Ebola virus. To determine subsequent viral titers in the serum, liver, and spleen, two mice were taken from VRP-vaccinated or control groups on each of days 1±5 after challenge, anesthetized and exsanguinated. Portions of the liver and spleen were removed aseptically, weighed, and ground in a sterile mortar. Viral titers in the sera and tissues were determined by plaque assay (Pushko et al., 2000).
• Persistence: None noted
• Side Effects: None
• Efficacy: GP-VRP was effective in protecting BALB/c mice against a lethal challenge with mouse-adapted Ebola virus (Pushko et al., 2000). Nine out of ten animals vaccinated with GP-VRP were protected (Pushko et al., 2000).

Guinea pig Response

• Host Strain: strain 2 and strain 13
• Vaccination Protocol: VRP were diluted in PBS and administered to inbred, strain 2 or strain 13 guinea pigs. Groups of five guinea pigs were inoculated subcutaneously (s.c.) at day 0 with a total of 0.5 ml containing 10^7 IU VRP at one (strain 2) or two (strain 13) dorsal sites. Challenge was carried out 4 weeks after final immunization with VRP. Guinea pigs were challenged s.c. with 1000 LD50 of guinea pig- adapted Ebola virus. Animals were observed daily for 60 days, and morbidity (determined as changes in behavior, appearance, and weight) and survival were recorded. Blood samples were taken
  on the days indicated after challenge and viremia levels were determined by plaque assay (Pushko et al., 2000).
• Persistence: None noted
• Side Effects: None noted
• Efficacy: At day 7 after challenge, both VRP-vaccinated groups had lower viremia titers than control animals. All mockvaccinated animals or NP-VRP-vaccinated animals became ill, and died at days 8±11 after challenge. However, three out of five guinea pigs vaccinated with GP-VRP showed no signs of illness and survived challenge, and the remaining two showed increased survival times. No clear relationship with survival and antibody titers was observed, as the pre-challenge ELISA and PRNT50 titers of the two GP-VRP-inoculated animals that died were equivalent to those of the three survivors (Pushko et al., 2000).