264 IMMUNOLOGY 



increases, wliile the yield decreases. Since alum toxoid is slowly 

 absorbed and remains in the body for a long period of time, while 

 the Ramon toxoid is rapidly eliminated, they believed that it may 

 be possible to immunize with one dose of alum toxoid. Theo- 

 retically tlie latter should be able to supply both the initial and 

 the secondary stimulus, whereas the Ramon toxoid is eliminated 

 before the appearance of antibodies when a secondary stimulus 

 is necessary for maximum antibody production and therefore a 

 second and perliaps a third injection of Ramon toxoid is necessary. 



This M'ork of (rlenny and Barr has been followed up by Wells, 

 Graham and Havens (1932) and more recently l)y Graham, Mur- 

 phree, and Gill (1933). The latter report that "a single injec- 

 tion of from 5 to 10 units of precipitated toxoid has rendered 171 

 or 92.4 per cent of 185 strongly Schick positive children Schick 

 negative. 



"Of 613 children, 592 or 96.6 per cent were Schick negative when 

 tested from two to four months after a single injection. The 

 original immunity status was unknown, but 72 per cent w^ere 

 pre-school children." Ramon (1940) regards the single injection 

 of toxoid as ineffective. 



Active-Passive Immunity. — ^Ramon (1940) has reviewed the 

 work he and his associates have done since 1925 on what they term 

 active-passive immunity to tetanus or diphtheria toxins respec- 

 tively. Ramon reports that active immunity can be produced by 

 injecting one or, better, two doses of toxoid sometime after the 

 simultaneous injections of the specific antitoxin and toxoid. 



They say that this procedure is not only of value in prophylactic 

 immunization but that they are recommending it as a new treat- 

 ment of acute tetanus or diphtheria. 



Recommendations of New York City Department of Health.* — 



As a result of extensive experience in diphtheria immunization 

 of children, the New York City Board of Health (1940) has made 

 recommendations which may be summarized as follows : 



1. Because of the passive immunity acquired from the mother 

 it is unwise to begin immunization of the child before the 

 ninth month of age. 



*New York Department of HeaUh, Quarterly Bulletin 8: 2, 1940. 



