132 IMMUNOLOGY 



fensive mechanisms of the respiratory tract. The results of their 

 work may be summarized as follows : 



1. By intranasal vaccination with a formalin-killed culture of 

 pneumococcus Type I or with an autolysate they were able to con- 

 fer practically complete protection against living pneumococci in- 

 troduced intranasally. 



2. Such nonspecific irritants as formalin, tannic acid, alum or 

 a paratyphoid vaccine used as intranasal stimulants did not con- 

 fer protection against intranasal infection with pneumococci. 



3. They found intranasal immunization superior to intragastric 

 immunization with a pneumococcal vaccine. 



4. They found no correlation between antibody titer in the blood 

 and intranasal immunity since intranasally vaccinated rabl)!ts, 

 having no demonstrable antibodies in their blood, resisted intra- 

 nasal infection. 



5. Successful intranasal vaccination did not prevent the aspira- 

 tion of intranasally instilled pneumococci into the lungs. It did 

 modify their passage from the lungs to the blood possibly because 

 of a general immunity and perliaps because of a locally enhanced 

 capacity of the lungs to inhibit growth and spread of the pneu- 

 mococci reaching them. 



6. They concluded that when rabbits are kept in a normal posi- 

 tion the virulent pneumococci instilled intranasally do not ])ass 

 through the epithelium of the upper respirator}^ tract but are 

 aspirated into the lungs and then enter the blood. 



7. They confirmed the work of Freund (1927) and Freund 

 and Whitney (1928) that, following the development of general 

 active or passive immunity, the antibodies are found rather uni- 

 formly distributed throughout the tissues and the ratio of tissue 

 antibod.y to serum antibody is usually between 1:10 and 1:15. 

 This is called the T :S ratio. 



8. When animals were vaccinated regionally as by intranasal 

 histillation the regional tissue (mucous membrane) serum ratios 

 of antibody was on an average of one to five. Cannon et al. state 

 that this suggests that perhaps the antibodies are formed locally 

 in regionally stimulated tissues and diffuse into the Ijlood. 



9. Cannon and Walsh (1938) followed \\\^ the work mentioned 

 above by studying the effect of many substances used in intra- 

 nasal medication on the local defensive mechanisms. Their work 



