Editorial: Fecal flora and resistance to invasive bacteria.

Abstract

The attenuated microbes used as vaccines have been derivatives or close relatives of the virulent organism, retaining enough immunologic similarity to induce specific immunity. Schneerson and Robbins, in this issue of the Journal, describe an interesting new approach: the induction of specific humoral immunity by colonization with a genetically unrelated but immunologically cross-reactive bacterium. The effort stems from a more fundamental question posed in previous reports by Dr. Robbins and colleagues, "how do we naturally acquire antibodies to the capsular polysaccharide of Haemophilus influenzae type b (H.i.b)?" They were struck by the apparent dilemma that these antibodies, which may be . . .