Trial of inactivated Japanese encephalitis vaccine in children with underlying diseases.

Two shots of inactivated Japanese encephalitis (JE) vaccine were given to children, 139 with underlying diseases and 42 healthy, and their antibody responses were studied by the neutralization test. Before vaccination, most of the vaccinees did not have antibody against JE virus. One month after the second vaccination, they were all seroconverted and showed considerably high neutralizing titres. One healthy child developed fever on the day of vaccination without any severe symptoms afterwards, and no side reactions were observed in the handicapped children. These results suggest that the current JE vaccine is safe and can induce a strong immune response even in handicapped children.