NATURAL AND ACQUIRED IMMUNITY 117 



In private practice, tetanus and diphtheria toxoids are employed 

 quite extensively to immunize young children. Since diphtheria 

 toxoid may give severe reactions in older individuals, it is cus- 

 tomary to use toxin-antitoxin in individuals over 8 to 10 years 

 of age. A more extensive discussion of immunization against 

 diphtheria and other toxemic diseases is given in later chapters. 



Immunization Programs. — It is common practice among pedi- 

 atricians and many general practitioners to follow a definite pro- 

 gram of immunization against the common contagious diseases 

 of childhood. While all physicians do not follow the same pro- 

 gram, a fairly typical one is that suggested hy Neff (1941). He 

 advises that (1) ''smallpox vaccination may be done at the time 

 of birth, either on the delivery table or when coming home from 

 the hospital, but there is sufficient immunity at that time so that 

 the site of vaccination may not take and may have to be repeated 

 at about three months of age. It is well in individual cases to make 

 it a rule to vaccinate at three months of age and repeat each week 

 if a take has not been obtained from the previous attempts. Vac- 

 cination against smallpox should l)e arranged for in any physical 

 examination of a person who has never been successfully vac- 

 cinated. This holds true of all scliool children npon admission. Il 

 is well to inspect the site of vaccination two days following the 

 application of the virus in order to see if there is a reaction of im- 

 munity. In such a case the explanation is furnished for a failure 

 to take in the next few days. It is probable that more successful 

 takes occur from using multiple sites at the time of vaccination. 



(2) "Whooping cough vaccine may be given at any age in child- 

 hood but as a routine it may be planned for at the age of six months 

 with weekly doses for the required number. There will be fewer 

 reactions if the total amount of vaccine to be used in the individual 

 case is divided up into five graduated doses. It is possible tliat by 

 the use of pertussis antigen, beginning immediately after exposure 

 of the child to a case of whooping cough, the child may be im- 

 munized successfully, or if unsuccessful that the disease when 

 developed will be milder than would otherwise have happened. 



(3) "Since most infants have relative diphtheria immunity until 

 about nine montlis of age it is well to begin active immunization at 

 that time, using three doses of regular diphtheria toxoid at three- 

 week intervals or alum precipitate toxoid, three doses at two- 



