MANUFACTURE OF VACCINES 571 



have resulted from careless methods employed in standardizing and 

 administering the vaccine. The most important objection to Pasteur's 

 anthrax vaccine is due to the danger involved in the use of the 

 living, attenuated anthrax organisms. 



Scalvo* advocates the use of the serum from animals actively im- 

 munized to anthrax. This method may be employed either in the 

 form of the immune serum alone, or the immune serum and anthrax 

 culture simultaneously. 



Eichhornf advises the use of antianthrax serum for curative 

 purposes, and the simultaneous treatment with antiserum and a care- 

 fully standardized spore vaccine as a preventive. When vaccine alone 

 is to be employed Eichhorn prefers the spore vaccine rather than the 

 ordinary Pasteur vaccine. 



TxjBERCDXOSis VACCINE. — ^Among the experimental products for 

 the prevention of animal tuberculosis may be mentioned von Behring's 

 "bovo-vaccine." The technic involved in the preparation of this 

 vaccine is not generally known. RomerJ describes the material as 

 being composed of the living tubercle organisms which are dried for a 

 period of thirty days in sealed glass tubes. After this process of attenua- 

 tion the organisms are injected, in carefully graduated doses, into 

 healthy calves. Field tests which have been made upon calves with 

 bovo-vaccine indicated unsatisfactory results. 



In human practice various tuberculins prepared both from the 

 bouillon culture and from the cellular elements of Bact. Hiberculosis 

 are used as therapeutic and diagnostic agents. Products containing 

 the cellular elements are similar in nature to bacterial vaccines. 



Bacterial Vaccines (Bacteeins) 



Opsonins may be defined as the elements in the blood or body fluids 

 which are capable of modifying invading bacteria in such a way that 

 they become ready prey to the leucocytes. In the presence of opsonins, 

 therefore, phagocytic activity is increased. Opsonins are apparently 

 distinct from agglutinins, lysins, and other analogous substances, 

 because different degrees of heat are necessary for their destruction. 

 Moreover, a given serum may agglutinate, or may exert lytic action, 

 without possessing opsonic activity. 



* Scalvo, Centralbl. f. Bakt., 1899, 26, p. 425.. 

 t Eichhorn, Bull. No. 340. U. S. Dept. of Agri. 

 j Romer, Beitrage z. Exp. Therapie, 1904, 7. 



