Passive transfer of acquired resistance to Schistosoma mansoni in laboratory mice

Abstract

Serum taken from mice 12–15 weeks after a primary infection of Sehistosoma mansoni transfers to normal recipients a partial resistance to subsequent schistosome challenge. The transfer of immunity is evident not oniy in the reduced recovery of mature parasites from the liver, but also in the diminished numbers of invading schistosomula recovered from the lungs. Since the recipients of immune serum exhibit a level of resistance equivalent on average to 47 % of that found in actively immunized animals, the results suggest that humoral factors play a major role in the effector mechanism of schistosome immunity.