Effectiveness of mouse brain-derived inactivated Japanese encephalitis vaccine in Thai National Immunization Program: a case-control study.

Mouse brain-derived, purified inactivated Japanese encephalitis vaccine (MB JEV) has been locally produced and introduced into Thai National Immunization Program (NIP) since 1990. However, MB JEV effectiveness has been concerned, since 30-40% of JE cases received JE vaccines were recently reported in two descriptive studies. Therefore, in 2010, a case-control study was designed to assess effectiveness of the MB JEV used in the NIP, among children aged 1 to <6 years.