Chimeric attenuated vaccine protects against Japanese encephalitis.

2003 DEC 10 - (NewsRx.com & NewsRx.net) -- Results from Phase 2 clinical trials for safety and immunogenicity indicate that a chimeric live, attenuated vaccine was protective against Japanese encephalitis.

"ChimeriVax-JE is a live, attenuated vaccine against Japanese encephalitis, using yellow fever (YF) 17D vaccine as a vector. In a double-blind phase 2 trial, 99 adults received vaccine, placebo, or YF 17D vaccine (YF-VAX). ChimeriVax-JE was well tolerated, with no differences in adverse events between treatment groups," an international team of scientists reports.

"Viremias resulting from administration of ChimeriVax-JE and YF-VAX were of short duration and low titer; 82 (94%) of 87 subjects administered graded doses (1.8-5.8 log[subscript]10) of ChimeriVax-JE developed neutralizing antibodies," stated Thomas P. Monath at Acambis Inc. in the United States and collaborators in the United Sates, Thailand, and the U.K. "A second dose, administered 30 days later, had no booster effect. Previous inoculation with YF did not interfere with ChimeriVax-JE, but there was a suggestion (not statistically significant) that ChimeriVax-JE interfered with YF-VAX administered 30 days later."

"A separate study explored immunological memory both in subjects who had received ChimeriVax-JE nine ...