PROPHYLAXIS 



One of us has prepared an attenuated live vaccine by heating 

 emulsions of agar cultures to 45° C. or 48° C. for one hour. 



A nucleo-proteid vaccine, according to Lustig and Galeotti's 

 method, can also be prepared. 



Tetravaccine (T.A.B.C.) — This is a vaccine prepared and used by 

 Castellani since 1909, and now frequently employed in various 

 countries as a prophylactic measure against cholera as well as 

 typhoid and the paratyphoid fevers. It has been adopted in the 

 Serbian Army since 1915. It is prepared as follows: — 



The growth of typhoid cultures is washed off with sterile 0*85 per 

 cent, salt solution, to which 0*5 per cent, carbolic acid has been 

 added; the emulsion so obtained is stored at room temperature 

 (18° to 20° C.) for twenty-four hours, and then standardized. To 

 standardize it the germs are counted by using a Thoma-Zeiss 

 apparatus, and sufficient carbolic salt solution is added to bring the 

 number of germs down to 2,000 millions per cubic centimetre. The 

 standardized emulsion is tested for sterility. The same procedure is 

 carried out with paratyphoid A and paratyphoid B cultures, these 

 two emulsions being also standardized to contain 1,000 million 

 germs per cubic centimetre. The above procedure is also carried 

 out with cholera, the emulsion of which, however, is standardized 

 to contain 4,000 million germs per cubic centimetre. The four 

 standardized emulsions when found sterile are mixed together in 

 equal proportions, and the vaccine will therefore contain per cubic 

 centimetre : — 



Typhoid . . . . . . . . 500 millions. 



Paratyphoid A .... . . 250 



Paratyphoid B . . . . . . 250 ,, 



Cholera . . . . . . . . 2,000 



Of this mixture, 0*5 to o«6 c.cm. are given under the skin of the 

 arm, or better into the loose tissue below the angle of the scapula, 

 the first time, and double the amount a week later. A third dose, 

 also J c.cm., given two weeks after the first, is of advantage, but not 

 essential for practical purposes. The amount of agglutinins for 

 each germ is about the same as if monovalent vaccine had been 

 injected. The protection for cholera seems to last for about six 

 months. 



Castellani has prepared also a glycero-tetra vaccine containing 2 per cent, 

 pure glycerine and standardized as to contain per c.c. typhoid 2,000 millions, 

 paratyphoid A 100 millions, paratyphoid B 1,000 millions, cholera 4,000 milhons. 

 Of this vaccine only one inoculation of i c.c. is given. 



A pentavaccine having in addition 300 millions of B. pestis may also 

 be prepared. The effect of the vaccine in man lasts for several 

 months (six to seven). 



Public Prophylaxis. — It is the duty of the State to attempt to 

 ward off cholera by preventing human beings introducing the germ. 

 This involves the careful watching of the frontiers, especially along 

 the lines of intercommunication, whether roads, railways, or water- 

 ways. Under the last heading must be included ships, boats, and 



