• Vaccine Name: AdsecV
• Target Pathogen: Yersinia pestis
• Target Disease: Plague
• Vaccine Ontology ID: VO_0000827
• Type: Recombinant vector vaccine
• V antigen gene engineering:
  • Type: Protein
  • Description:
  • Detailed Gene Information: Click Here.
• Preparation: The Y. pestis V antigen gene with mammalian-preferred codons was synthesized by overlap polymerase chain reaction and fused to the human Ig signal sequence for extracellular secretion. The V antigen gene was cloned into a recombinant Ad5–based vector (E1a, partial E1b, and partial E3 deletion), to generate AdsecV. AdNull was used as a control vector with identical backbone but no transgene. The vectors were produced in 293 cells and were purified by double CsCl gradient centrifugation. Dosing was based on particle units (pu), the physical number of Ad particles as measured by spectrophotometry. V antigen was purified as a histidine-tag fusion by use of a Ni-NTA Superflow Column (Qiagen) under native conditions (Chiuchiolo et al., 2006).
• Virulence:
• Description: Ad vectors are excellent candidates for vaccine platforms as they transfer genes effectively to antigen-presenting cells (APCs) in vivo, with consequent activation of APCs, thus conveying immune adjuvant properties and inducing strong, rapid humoral and cellular immune responses against the transgene product (Chiuchiolo et al., 2006).

Mouse Response

• Host Strain: Female, seven-week old BALB/c mice were obtained from Taconic.
• Vaccination Protocol: Mice were immunized in a single vaccination by 2 intramuscular injections, with 50 microliter of the vaccine preparation divided evenly between the quadriceps on each side. AdsecV doses ranged from 10^8 to 10^11 pu. Ad vectors were diluted with saline to the specified dose (Chiuchiolo et al., 2006).
• Persistence: AdsecV induces high IgG titers within 2 weeks after a single immunization (Chiuchiolo et al., 2006).
• Side Effects: No side effects noted.
• Challenge Protocol: Four weeks after vaccination, the mice were infected intranasally with 3 × 10^3 cfu of Y. pestis strain CO92. Assessment of the data at 15 days after challenge showed that the mortality of mice was dependent on the vaccine dose.
• Efficacy: All of the mice in the group vaccinated with 10^11 pu of AdsecV survived the Y. pestis challenge. The 10^9- and 10^8-pu doses were not protective; the mice in those groups died according to the same time frame as did the mice in the control groups that received either saline or 10^11 pu of AdNull. Thus mice immunized with a single dose of AdsecV are shown to be protected from a lethal intranasal challenge of Y. pestis (Chiuchiolo et al., 2006).