61 VIRUSES AND HDUAN WELFARE 



winter of I94-3-44, a study was carried out with about 12,000 raembere of the armed 

 forces assigned to ASTP units in colleges and universities located in many sect- 

 ions of the country. About 6,000 of these were inoculated with influenza vaccine 

 and about 6,000 with salt solution. Within a few weeks after the conpletion of 

 the vaccination an influenza epidemic spread across the country. When the inci- 

 dence of influenza was studied in botli the vaccinated group and the control group 

 inoculated with salt solution, it was found that 7«ll/f of the 6,000 unvaccinated 

 individuals developed clinically recognizable influenza. On the other hand, only 

 2.22^ of the vaccinated group developed influenza. Thus, this experiment demons- 

 trated that the odds against developing influenza were increased by a factor of 

 more than 3 'to 1 ^y this vaccine. Studies carried out by Hirst, Rlckard and 

 -H'riedewald show that even a year after vaccination the incidence of influenza 

 is 1/3 less than in unvaccinated controls. These favorable statistics leave lit- 

 tle doubt that the time is near at hand when influenza can be regarded as one of 

 the conquered diseases. 



Another disease which can be listed among the vanquished is measles. The 

 approach to the conquest of measles is entirely different from that utilized for 

 any other virus disease considered in this chapter, tleaslea is a very widely- 

 spread disease. The vast majority of the people have had it at one time or an- 

 other. Ordinarily it is not particularly dangerous, but a certain fraction of 

 Individuals develop complications which can be of a very serious nature. Thus, 

 the control of measles is a matter of considerable importance. The fact that 

 measles is of almost universal occurrence provides the means for controlling the 

 disease. Virtually all normal adults are immune, that is, they have v/ithin their 

 blood stream anti^bodies to measles. Experiments carried out during several years 

 have shown that the course of a measle infection can be modified very consider- 

 ably by the injection of serum, from patients recently recovered from the disease. 

 Such serum is relatively high in measle antibody content. 



Studies carried out in many laboratories over the past 20 years have gradu- 

 ally shed light upon the composition of human blood. It has been found that the 

 fluid component is made up essentially of five proteins. These are called al- 

 bumin, fibrinogen, alpha-globulin, beta-globulin and gamma- globulin. The elect- 

 rophoresis apparatus was one of the most effective tools for resolving the con- 

 stituents of blood. It was learned in the course of these studies that the anti- 

 bodies to disease are generally associated with the gamma- globulin fraction. 

 During the war, when human blood was collected in hugh quantities by the Red Cross 

 primarily for the treatment of shock, an attempt was made at the Harvard labor- 

 atories and elsewhere to devise means for the isolation from this human blood of 

 the constituent effective for shock. This constituent is serum albumin. These 

 fractionating procedures provided means for separating the albumin from the other 

 constituents which play only a minor role in the control of shock. Therefore, 

 these constituents were made available for other purposes. Since almost all hu- 

 man beings are Immume to measles, it was only natural to determine whether or not 

 those fractions of the processed human blood richest in gamma-globulin would be 

 an effective m.eans of controlling measles. This turned out to be the case. Uamma- 

 globulin has been made available to the civilian public. Several fairly extensive 

 studies have been carried out. In one study conducted in Boston, it was shown 

 that the gamma-globulin fraction could be used to prevent entirely the develop- 

 ment of measles in exposed children or it could be used to modify the course of 

 the disease in order to produce only a mild infection. It was found that if 

 1/10 cubic centimeter of the gamma- globulin rich fraction of processed blood was 

 Injected per pound of body weight, the individuals will be completely protected. 

 A quarter of this amount will result in a very mild disease. In another study 

 carried out in New York City on 8l4 exposed individuals, 2 cc . of gamma- globulin 

 was administered uniformly to patients between six months and six years of age. 

 Sixty-five individuals in a control group received no gamma-globulin. The re- 

 sults are listed in Table VI. They demonstrate conclusively the effectiveness 

 of gamma-globulin for the prevention or the modification of measles. 



