Immunization of Laboratory Workers with Purified Trivalent Equine Encephalomyelitis Vaccine

Abstract

Summary A partially purified trivalent vaccine of chick embryo origin was prepared and used to immunize laboratory personnel against Eastern, Western and Venezuelan strains of equine encephalomyelitis. Individuals who had not previously received equine encephalomyelitis vaccines were given 0.75 ml subcutaneously, while those who had received equine encephalomyelitis vaccines in the past were given a single booster of 0.1 ml intradermally or 0.75 ml subcutaneously. Antibody responses to annual booster immunizations were elicited satisfactorily when given by either the intradermal or subcutaneous routes of inoculation. The use of one intradermal trivalent booster to maintain immunity against these three diseases helps to simplify the immunization procedure.