158 
1 where we should have concern regarding various types of 
2 pathogens. 
3 In 1970, as an individual in the Commissioned 
4 Corps of the Public Health Service, I was assigned to the 
5 Shigella vaccine development program at the University of 
0 Maryland, where various Shigella dysenteriae vaccines 
7 were tested. These were in the early years — organisms 
8 that were prepared by recombining genetic material 
9 between virulent Shigella organisms and E. col i . The 
10 work was based on findings of Dr. Formol at the Walter 
11 Reed Institute of Research. Dr. Formol was able to 
12 identify the steps involved in the pathogenesis of 
13 dysentery, and was able to actually identify the genes 
14 within the Shigella . Since E. coli is a first cousin 
15 of Shigell a, he was able to transfer the homologous 
15 genetic material from E. coli into the Shigella germs. 
17 These recombined vaccine strains were fed. Of six 
18 different vaccine candidates fed, two were attenuated 
19 in individuals, and in healthy adult volunteers, and 
2q were well tolerated for or associated with some adverse 
21 reactions. The adverse reactions, though, were milder 
22 or no different than a dysentery syndrome were virulent 
23 organisms fed. 
24 In more recent studies, the reverse has been 
25 done. The surface coverings of Shigella , what we believed 
[250] 
