title: A multisystem approach for development and evaluation of inactivated vaccines for Venezuelan equine encephalitis virus (VEEV).
abstract: A multisystem approach was used to assess the efficiency of several methods for inactivation of Venezuelan equine encephalitis virus (VEEV) vaccine candidates. A combination of diverse assays (plaque, in vitro cytopathology and mouse neurovirulence) was used to verify virus inactivation, along with the use of a specific ELISA to measure retention of VEEV envelope glycoprotein epitopes in the development of several inactivated VEEV candidate vaccines derived from an attenuated strain of VEEV (V3526). Incubation of V3526 aliquots at temperatures in excess of 64 degrees C for periods >30 min inactivated the virus, but substantially reduced VEEV specific monoclonal antibody binding of the inactivated material. In contrast, V3526 treated either with formalin at concentrations of 0.1% or 0.5% (v/v) for 4 or 24 h, or irradiated with 50 kGy gamma radiation rendered the virus non-infectious while retaining significant levels of monoclonal antibody binding. Loss of infectivity of both the formalin inactivated (fV3526) and gamma irradiated (gV3526) preparations was confirmed via five successive blind passages on BHK-21 cells. Similarly, loss of neurovirulence for fV3526 and gV3526 was demonstrated via intracerebral inoculation of suckling BALB/c mice. Excellent protection against subcutaneous challenge with VEEV IA/B Trinidad donkey strain was demonstrated using a two dose immunization regimen with either fV3526 or gV3526. The combination of in vitro and in vivo assays provides a practical approach to optimize manufacturing process parameters for development of other inactivated viral vaccines.
authors.affiliation: DynPort Vaccine Company LLC (DVC), A CSC Company, 64 Thomas Johnson Drive, Frederick, MD 21702, USA. dfine@csc.com
authors.forename: Donald L
authors.initials: DL
authors.lastname: Fine
authors.forename: Erin
authors.initials: E
authors.lastname: Jenkins
authors.forename: Shannon S
authors.initials: SS
authors.lastname: Martin
authors.forename: Pamela
authors.initials: P
authors.lastname: Glass
authors.forename: Michael D
authors.initials: MD
authors.lastname: Parker
authors.forename: Brad
authors.initials: B
authors.lastname: Grimm
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002460:Cell Line; D006224:Cricetinae; D004202:Disinfectants / Q000494:pharmacology; D004666:Encephalitis Virus, Venezuelan Equine / Q000187:drug effects / Q000276:immunology* / Q000472:pathogenicity* / Q000528:radiation effects; D004685:Encephalomyelitis, Venezuelan Equine / Q000821:virology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005557:Formaldehyde / Q000494:pharmacology; D005720:Gamma Rays; D006358:Hot Temperature; D051379:Mice; D008807:Mice, Inbred BALB C; D016019:Survival Analysis; D013997:Time Factors; D015164:Vaccines, Inactivated / Q000276:immunology; D010948:Viral Plaque Assay; D014765:Viral Vaccines / Q000276:immunology*; D014774:Virulence; D014776:Virus Cultivation; D038301:Virus Inactivation
chemical_list: D000914:Antibodies, Viral; D004202:Disinfectants; D015164:Vaccines, Inactivated; D014765:Viral Vaccines; D005557:Formaldehyde