VACCINATION AGAINST TYPHOID FEVER. 



BY HENRY ALBERT. 



The term vaccination was originally used to designate the introduc- 

 tion of material from pustules of cows affected with cowpox into the 

 human being to protect against smallpox. Such produced a mild form 

 of the disease and conferred immunity to the more severe type as rep- 

 resented by smallpox proper. The vaccine represents, then, a weak- 

 ened or attenuated form of the virus. The term, as now used, applies 

 to the virus of any infectious disease, — the virulence of which virus has 

 been diminished. 



In 1886, Simmons and Frankel immunized small animals with living 

 cultures of typhoid bacilli. The use of living cultures of bacteria even 

 though their virulence has been diminished is obviously objectionable 

 for immunizing human beings. It has moreover been shown that for 

 certain diseases, dead bacteria will immunize quite as efficiently as 

 living bacteria. The first vaccinations of human beings against typhoid 

 fever were made with killed typhoid bacilli by Wright in 1896. Ty- 

 phoid vaccines were used to some extent in the Boer war in 1900 but 

 the value of the procedure was not thoroughly recognized until 1904 

 when the English and Germans began to use it extensively among the 

 soldiers. In 1908 it was introduced into our own army — the submission 

 to vaccination being at first entirely voluntary but was made compulsory 

 in 1911. . 



To date more than 14,000 American soldiers and many thousands 

 more of the English anl German army have been vaccinated with very 

 good evidence of protection against typhoid fever. In the earlier work 

 the number of cases of typhoid among the vaccinated was about one- 

 half that among the unvaccinated and the number of deaths from that 

 disease only about one-fourth as high. With better technique, still 

 better results have been obtained as shown by the fact that the recent 

 figures indicate that the number of cases of and deaths from typhoid 

 fever among the vaccinated is only about one-tenth as great as among 

 the unvaccinated kept under the same conditions. 



