Evaluation of a New, Inactivated Venezuelan Encephalitis Virus Vaccine (C-84) in Man.

摘要

A new, formalin-inactivated Venezuelan encephalitis (VE) virus vaccine (C-84), prepared from the attenuated vaccine (TC-83) strain of virus, was tested in man. Only occasional, mild, local and systemic reactions were noted in 32 volunteers; no meaningful changes occurred in clinical laboratory values. The vaccine augmented preexisting VE virus serum neutralizing antibody titers in seropositive recipients of TC-83 vaccine; it induced antibody in previously immunized seronegative subjects who were refractory to TC-83; and it induced high titers of neutralizing antibody in nonimmunes after one primary and two booster vaccinations. Circulating antibody persisted for at least 14 months in these persons. The neutralizing antibody produced after one dose of C-84 in immunes and after booster doses in nonimmunes had broad cross-reactivity within the VE virus complex. The C-84 vaccine induced a VE virus-specific lymphocyte transformation response only in individuals without prior exposure to an inactivated VE vaccine. The vaccine was safe, and immunological results showed it to be highly antigenic in healthy immune and nonimmune adults. (Author)