V. Evaluation of Cross-Immunity against Type 1 Dengue Fever in Human Subjects Convalescent from Subclinical Natural Japanese Encephalitis Virus Infection and Vaccinated with 17D Strain Yellow Fever Vaccine
Successive samples of serum of rabbits infected with S. japonicum, and of uninfected controls, were fractionated by paper electrophoresis and changes were observed for a period of seven months. In the early stages of the disease, before deposition of eggs, no notable changes in the serum-protein fractions were observed. However, beginning with early oviposition a marked increase in total proteins was observed. At this time there were also a sudden relative decrease in albumin and increase in gamma-globulin fractions which remained essentially unchanged up to the end of the experiment, 6 months following infection. Fractionations of sera from persons with proven schistosome infection showed significant increases in total protein and in the relative proportions of alpha-2, beta and gamma-globulin fractions, with a corresponding decrease in the relative proportions of albumin.