• Vaccine Name: GP and NP
• Target Pathogen: Ebola virus
• Target Disease: Ebola hemorrhagic fever
• Vaccine Ontology ID: VO_0004073
• Type: VEEV Replicon
• Preparation: The Ebola NP and GP genes from the Mayinga strain of Ebola virus were derived from pSP64- and pGEM3Zf(-)-based plasmids. The BamHI±EcoRI (2.3 kb) and BamHI±KpnI (2.4 kb) fragments containing the NP and GP genes, respectively, were subcloned into a shuttle vector digested with BamHI and EcoRI within a polylinker sequence flanked by ClaI sites. For cloning of the GP gene, overhanging ends produced by KpnI (in the GP fragment) and EcoRI (in the shuttle vector) were made blunt by incubation with T4 DNA polymerase. From the shuttle vector, NP or GP genes were transferred as ClaI-fragments into the ClaI site of the replicon clone, resulting in plasmids encoding the NP or GP gene in place of the VEE structural protein genes (Pushko et al., 2000).
• Virulence:
• Description: This immunogen is composed of RNA replicon particles derived from an attenuated strain of Venezuelan equine encephalitis virus (VEEV) expressing EBOV glycoprotein and nucleoprotein (Geisbert et al., 2002).

Monkey Response

• Host Strain: Cynomolgus macaques
• Vaccination Protocol: Groups of three cynomolgus macaques were vaccinated with VRP that expressed EBOV GP, EBOV NP, a mixture of EBOV GP and EBOV NP, or a control antigen (influenza hemagglutinin) that has no effect on EBOV immunity. Animals were vaccinated by subcutaneous injection of 10^7 focus-forming units of VRP in a total of 0.5 mL at one site. Vaccinations were repeated 28 days after the first injection and 28 days after the second (Geisbert et al., 2002).
• Persistence: None noted
• Side Effects: None noted
• Efficacy: These results indicate that rodent models of EBOV hemorrhagic fever do not consistently predict efficacy of candidate vaccines in nonhuman primates, perhaps because the disease course in rodents differs from that reported in human and nonhuman primates (Geisbert et al., 2002).
• Description: All animals, including the four untreated macaques, were challenged with 1,000 PFU of EBOV 49 days after the third vaccine dose. At postchallenge day 3, all animals became ill; two animals from each vaccination group (i.e., GP, NP, GP + NP, influenza HA) died on day 6, and the remaining animals died on day 7 (Geisbert et al., 2002).