PROTECTIVE ACTION OF PASSIVELY TRANSFERRED IMMUNE SERUM AND IMMUNOGLOBULIN FRACTIONS AGAINST TISSUE INVASIVE STAGES OF DWARF TAPEWORM, HYMENOLEPIS NANA

Serum from mice which received a single oral infection of Hymenolepis nana eggs acquired significant immune activity against subcutaneously growing larvae of this parasite within 7 days, and the maximum level, which was reached by 14 days, was maintained at least 14 days longer. Serum immune activity was manifested by inhibition of larval development at stage I. The time of onset of serum potency demonstrated by passive transfer paralleled the onset of significant resistance to subcutaneous challenge in mice orally infected with a comparable egg dose, and it was concluded these phenomena were causally related. After gel filtration of potent serum, antiparasite activity was found to be associated with the IgG (7S) immunoglobulin fraction. © 1969.