Sporozoite and normal salivary gland induced immunity in malaria

Abstract

STUDIES using sporozoites as antigenic material to induce protection against malaria have been relatively scarce compared with those employing antigens of the blood stages. Many workers1-5 have reported considerable protection against challenging homologous sporozoites of Plasmodium gallinaceum. Richards4, using three injections of sporozoites exposed to ultraviolet, dried or treated with formalin, found at least eighteen birds out of twenty were protected, but with freeze-thawed sporozoite material he found only fifteen out of twenty protected. By using six to seven injections of X-irradiated sporozoites of Plasmodium berghei, Nussenzweig et al. 6,7 obtained 90-100% protection when the animals were challenged with 2,000 sporozoites two weeks after the last injection. © 1972 Nature Publishing Group.