Hyperacute Allergic Encephalomyelitis: Adjuvant Effect of Pertussis Vaccines and Extracts

Pertussis vaccine acts as an adjuvant for development of allergic encephalomyelitis in rats, accelerating and intensifying it, and converting it to a hyperacute form. The active principle in pertussis vaccine was resistant at 56°C but labile at 80°C. It was absent from endotoxin preparations but was present in partially purified histamine sensitizing factor (HSF). It was present in vaccines and extracts in proportion to their HSF content. The active principle may be identical with HSF or closely associated with it.