• Vaccine Name: NP-VRP
• Target Pathogen: Ebola virus
• Target Disease: Ebola hemorrhagic fever
• Vaccine Ontology ID: VO_0011387
• Type: Recombinant vector vaccine
• Status: Research
• EBOV NP gene engineering:
  • Type: Recombinant vector construction
  • Description:
  • Detailed Gene Information: Click Here.
• Preparation: The Ebola NP gene from the Mayinga strain of Ebola virus were derived from pSP64-based plasmid. The BamHI±EcoRI (2.3 kb) fragment containing the NPgene, was subcloned into a shuttle vector digested with BamHI and EcoRI within a polylinker sequence flanked by ClaI sites. From the shuttle vector, NP gene was transferred as ClaI-fragments into the ClaI site of the replicon clone, resulting in plasmids encoding the NP gene in place of the VEE structural protein genes (Pushko et al., 2000).
• Immunization Route: Intramuscular injection (i.m.)

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).
• Efficacy: At day 7 after challenge, NP-VRP-vaccinated group had lower viremia titers than control animals. All mock vaccinated animals or NP-VRP-vaccinated animals became ill, and died at days 8±11 after challenge (Pushko et al., 2000).

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).
• Efficacy: NP-VRP was effective in protecting BALB/c mice against a lethal challenge with mouse-adapted Ebola virus (Pushko et al., 2000). All mice vaccinated with NP-VRP survived the challenge with no signs of illness (Pushko et al., 2000).