A purified inactivated Japanese encephalitis virus vaccine made in vero cells

A second generation, purified, inactivated vaccine (PIV) against Japanese e ncephalitis (JE) virus was produced and tested in mice where it was found t o be highly immunogenic and protective. The JE-PIV was made from an attenua ted strain of JE virus propagated in certified Vero cells. purified. and in activated with formalin. Its manufacture followed current GMP guidelines fo r the production of biologicals. The manufacturing process was efficient in generating a high yield of virus, essentially free of contaminating host c ell proteins and nucleic acids, The PIV was formulated with aluminum hydrox ide and administered to mice by subcutaneous inoculation. Vaccinated animal s developed high-titered JE virus neutralizing antibodies in a dose dependa nt fashion after two injections. The vaccine protected mice against morbidi ty and mortality after challenge with live, virulent. JE virus, Compared wi th the existing licensed mouse brain-derived vaccine. JE-Vax. the Vero cell -derived JE-PIV was more immunogenic and as effective as preventing encepha litis in mice. The JE-PIV is currently being tested for safety and immunoge nicity in volunteers. (C) 2001 Published by Elsevier Science Ltd.