Five human volunteers were infected with the Chesson strain of vivax malaria through the bites of heavily infected mosquitoes. Five other volunteers were similarly infected with a Southern Rhodesian strain of falciparum malaria. Antibody production, as measured by the fluorescent antibody method, and changes in the serum protein fractions separated by paper electrophoresis were studied during the course of the initial infection and multiple relapses or recrudescences of the malaria infections.
In both types of infection antibodies first appeared 3 to 9 days after the onset of patent parasitemia and reached maximum titers of 1:640 to 1:2560 within 8 to 21 days of patency. Antibodies persisted at titers of 1:10 to 1:160 for up to 252 days after the end of patent parasitemia.
Each episode of parasitemia was associated with a transient rise in the gamma globulins and alpha1 globulins, and a transient decrease in the albumin and alpha2 globulins. The beta globulins showed no consistent changes. Elevated gamma globulin levels tended to persist if clinical evidence of immunity was present but decreased rapidly to normal levels if evidence of immunity was lacking.
The initial increase in gamma globulins closely paralleled the appearance of antibodies. However, later in the course of the infections there appeared to be little correlation between the gamma globulin and antibody levels.
Present address: Department of Medicine, University Hospital, Syracuse 10, New York.
Malaria Project, LPC, NIAID, NIH, U. S. Penitentiary, Atlanta, Georgia.