Japanese encephalitis purified vaccine.

Abstract

uMMARY A procedure for purification of Japanese encephalitis (IE) vaccine from infected mouse brains is described.The method is based on t\\.o cycles of ultraccntrifugation of active carbon-treated protamine extract of infected brain hornogenate.This gives a very effective \, accine containing very little protein nitrogen.Purified vaccine is rather labile in phosphate-buffered saline, btit can be stabilized by adding gelatine to TC Liedium 199 buffered with phosphate.The absence of encephalitogenic substances in the vaccine \\. as demonstrated.Preliminary successful results on similarly purified vaccine from brains of mice infected with the current IaGAr#01 straii\ of Japanese encephalitis \, irus, instead of the Lisual \al<ayama vaccine strain, are also described.BIKE\ 10LRNAi, V01.11 \0.I 1968 6. antiseirr a) Anti-mouse brain serum : Rabbits were jinin unized 3 times Intramuscularl\, at intervals of 4 \\'eeks \\.itIT a freslT hornogenate of 0.5 g (wet \\.t) of normal mouse brain in complete Freund's adju\'ant The rabbits \\.ere bled 3 \\, eeks after the last injeclion b) Anti-ultracentriftige-purified \, accine serum ; Rabbits were jinmunized intravenously 3 times, e\, er\, other da\, \\, ith I inI of 7 times concentrated purified \, accine.Then after an interval of 2 weeks,