Transmission of Japanese encephalitis virus in Hong Kong.

1. Pigs are likely to be the main amplifying host for Japanese encephalitis virus. 2. The success of a swine vaccination programme depends on the timing of the loss of maternal antibody protection and seasonal dynamics of the vector population. 3. Vaccination may be ineffective in the face of strong natural infection because of the variability in timing of the loss of maternal antibody protection.4. Evidence in support of swine vaccination as a human health intervention was not found.