On Local and General Immunity

Abstract

There is considerable evidence that natural resistance, and whatever grade of active acquired immunity may exist against streptococcus infections, is due to a mechanism that differs from that which is operative in many other bacterial infections. It seems likely that ignorance of what constitutes this difference accounts to a large extent for the failure to obtain any strikingly successful results in the prevention or cure of any of the manifold forms of streptococcic disease.

There seems to us an increasingly generalized acceptance of the main points of Metchnikoff's phagocytic theory of immunity, at least in the following features: the majority of bacteria that invade the animal body are dealt with first by the mobile and ubiquitous polymorphonuclear leucocytes. These phagocytes either act alone or in conjunction, particularly in conditions of acquired immunity, with the tropinizing substances present in serum. There seem, however, to be instances of immunity in which neither of these two factors seem particularly operative.