THE NEUTRALIZATION OF ENCEPHALITIS VIRUS (ST. LOUIS, 1933), BY SERUM 12

Abstract
Sera from 126 of the 1097 patients diagnosed as having encephalitis during the 1933 epidemic in St. Louis were tested for their power to neutralize the virus of St. Louis encephalitis. In 69% neutralization was demonstrated while 9% were found to be doubtfully positive. 33% of the sera obtained from 217 individuals of the epidemic area who had no history of encephalitis were also found to neutralize the virus. The group was composed of persons who had direct contact with encephalitis patients and others without known contact; no significant difference was found in the 2 groups.