VACCINES IN PROPHYLAXIS OF DISEASE 189 



infections after vaccination occur in those in 

 whom the regard for cleanliness is slight, and 

 who neglect to properly protect the wound. In 

 recent years, owing to the improved quality of 

 the Vaccine Virus, the introduction of aseptic 

 methods, and better after-care, serious compli- 

 cations are very rare. In any case, the danger 

 connected with vaccination is infinitesimal when 

 compared with the benefit conferred. 



REVACCINATION 



After a varying number of years, usually five 

 or more, the immunity conferred by the primary 

 vaccination is partially or, less often, completely 

 lost. Every person should, therefore, be revac- 

 cinated one or more times. A good rule is to 

 vaccinate in infancy, again upon entering 

 school, and thereafter at intervals of five years 

 until adult life is reached. If smallpox appears 

 in a community, all the inhabitants should at 

 once be vaccinated except those who have been 

 successfully vaccinated within one year. 



It should be remembered and taught by phy- 

 sicians that systematic and successful revacci- 

 nation is just as important for the protection 

 from smallpox as is a successful first vaccina- 

 tion. 



