virulent sh . flexneri strain 2a , sh . sonnei strain , attenuated sh . flexneri vaccine strain 2a 516m , and sh . sonnei vaccine strain 6s ( isolated by yu . a. belaya ) , as well as streptomycin-dependent sh . flexneri strain 2a 1605/3 ( isolated by v. v. sergeev ) were introduced into the ligated loops of the rabbit ileum .
C0042211
attenuated
C0042210
vaccine