The evidence just reviewed makes abundantly clear that not only does immunity exist in malaria, but that this immunity, in lower animals at least, can be induced artificially with vaccines prepared from killed organisms. Dr. McGregor and his colleagues, as he will describe, have demonstrated, unequivocally, the successful passive transfer of specific immunity in humans with human γ globulin. Thus, there is every reason to believe that the development of a successful antimalarial vaccine depends only on the exertion of the requisite amount of the right kinds of effort—and a little bit of luck. This conclusion can be called optimistic, however, only if one does not question too closely the meaning of “requisite amounts,” “right kind,” “little bit.”
I am, thus, in complete agreement with Dr. Powell's statement that “…active immunization against malaria merits extensive investigation.”.
Department of Immunochemistry, Division of Communicable Disease and Immunology, Walter Reed Army Institute of Research, Washington, D. C.