T0XIX8 AND ANTITOXINS 291 



measles is of great value. It permits of the development of an 

 attenuated form of the disease and is usually available. They 

 found that 6.0 c.c, of convalescent serum completely protected 

 73 per cent of the childi-cn who received it, wliile the remainder 

 came down with mild attacks. Whole blood from adults wlio had 

 previously had measles was used in amounts of 30 c.c. Of 56 

 children so treated after exposure to measles 77 per cent de- 

 veloped a mild form of measles. The Tunnicliff serum was ad- 

 ministered but failed to protect or to modify the disease. 



Importance of Epidemiological Factors. — Karelitz and Schick 

 (1935) are of the opinion that epidemiologic factors must be 

 taken into consideration in measles prophylaxis. They review 

 the literature bearing upon this subject and report tlic results of 

 their studies. They find that in homes where good hygiene is 

 practiced there is a greater percentage of patients showing pro- 

 tection from the administration of convalescent immune seruni 

 than in homes where j)oor hygienic conditions are found. 



I'sK of Pooled Placental Blood. — Largely to overcome the dif- 

 ficulty of obtaining a serum having protective value in measles, 

 ►Salazar de Sanza (1932) and Dulitskiy (1932) suggest the use of 

 pooled placental blood or serum. They report quite favorable 

 results from their respective studies of its potency, although they 

 encountered some difficulty in sterilizing it without reducing its 

 therapeutic value. As a result of the experimental work of 

 McKhann and Chu (1933) these objections have been overcome 

 and a concentrated extract, called immune globulin, is being pre- 

 pared for clinical use by at least some of the manufacturers of 

 biologic products. 



Poliomyelitis. — It is now quite well established that poliomye- 

 litis is a virus disease. Park (1928) states that from the time that 

 Flexner and Lewis (1910) and also Levaditi and Landsteiner 

 (1910) discovered that serum from convalescent monkeys con- 

 tains virucidal substances, it has been held that convalescent 

 serum, when administered early, is of prophylactic and thera- 

 peutic value. This was also the opinion of Aycock et al. as late as 

 1929. In 1931 there occurred an extensive epidemic of polio- 

 myelitis in New York. Park carried out an extensive and con- 

 trolled experimental investigation of tlie ^•alue of convalescent 



