Immune response to live-attenuated Japanese encephalitis vaccine (JE-CV) neutralizes Japanese encephalitis virus isolates from south-east Asia and India.

Background: During clinical development of the licensed Japanese encephalitis chimeric virus vaccine (JE-CV), the neutralization capacity of vaccine-induced antibodies was assessed against the vaccine virus and against well characterized wild-type (wt) viruses isolated between 1949-1991. We assessed whether JE-CV-induced antibodies can also neutralize more recent wt Japanese encephalitis virus (JEV) isolates including a genotype 1 isolate.

Methods: Sera from 12-18 month-old children who received a single dose of JE-CV in a phase III study in Thailand and the Philippines (ClinicalTrials.