Successful immunization against the sexual stages of Plasmodium gallinaceum.

Gametocyte infectivity and oocyst development of the avian malaria parasite, Plasmodium gallinaceum, can be reduced or eliminated in mosquitoes by immunizing the chickens on which the mosquitoes feed with infected red blood cells that have been treated with formalin or x-rays. Protection of the mosquito appears to be related to the immobilization of the microgametes in its gut and is associated with the immunoglobulin G fraction of serum.