Efficacy of prevention of Japanese encephalitis by injection of Japanese encephalitis vaccine produced by the National Institute of Epidemiology and Hygiene in Gia L­¬ng district, B¾c Ninh province during 1993-1999

ABSTRACT

The rate of Japanese encephalitis in Gia L­¬ng district was 21.4/100000, higher 4-5 times than other regions in the country. The disease occurred mainly in children under 15 years. After first 3 years (1993-1995) of injection, the rate of Japanese encephalitis was not reduced due to the rate of vaccination. However, because the rate of vaccination was increasingly during 1996-1999, the morbidity rate was gradually reduced from 21.4/100000 (in 1993) to 12.3/100.000 (in 1996) and 1.4/100.000 (in 1999). After 7 years of vaccination there was only one case received 2 injections of Japanese encephalitis vaccine suffered Japanese encephalitis among 109 total cases of Japanese encephalitis. The efficacy of vaccine of institute of epidemiology and hygiene was 99.3%.