title: Formalin-inactivated Venezuelan equine encephalomyelitis (Trinidad strain) vaccine produced in rolling-bottle cultures of chicken embryo cells.
abstract: Formalin-inactivated Venezuelan equine encephalomyelitis vaccine was prepared from virus grown in rolling-bottle cultures of chicken embryo cells. Trinidad strain virus was propagated in these cultures with a maintenance medium consisting of serum-free medium 199 containing 0.25% human serum albumin (USP) and antibiotics. Manipulation of multiplicity of inoculum (0.06 to 0.00006) and maintenance medium volume (100 to 300 ml) resulted in high-titered virus yields and only moderate cell destruction when fluids from infected cultures were harvested at 18 to 24 hr. The virus was inactivated at 37 C by 0.05% Formalin within 8 to 10 hr and with 0.1% Formalin within 6 to 8 hr. Single dose, antigen extinction tests in mice performed with 30 small-scale vaccine lots showed excellent potency at either Formalin concentration with inactivation periods ranging from 24 to 96 hr.
mesh_terms: D000818:Animals; D002642:Chick Embryo; D003470:Culture Media; D046508:Culture Techniques; D004666:Encephalitis Virus, Venezuelan Equine / Q000187:drug effects / Q000254:growth & development / Q000276:immunology*; D005557:Formaldehyde / Q000494:pharmacology; D051379:Mice; D014765:Viral Vaccines / Q000494:pharmacology / Q000592:standards; D014776:Virus Cultivation
chemical_list: D003470:Culture Media; D014765:Viral Vaccines; D005557:Formaldehyde