Anthrax crude protective antigen (PA) was used in this study as an adjutant
with Brucella abortus S19 strain vaccine in a ratio of 1:1 to immunize mice in
dose of 0.1 ml s/c in order to decrease side effects of S19 vaccine and also to
enhance its immunogenicity. Three groups of mice were immunized with the
mixture (composed of anthrax PA +S19, S19 alone, and sterile PBS solution as
a control. They were compared concerning cellular and humeral immunity. The
group treated with the mixture was the best regarding skin test, the difference of
thickness was 1.51± 0.103 mm after 24 h and 1.14± 0.103 mm and 0.89± 0.100
mm after 48 and 72 h, respectively. As well as that group revealed the highest
antibody titer, which reported 0.7153± 0.08 nm as compared with 0.3743± 0.06
nm in S19 group. These findings were verified by studying the
histopathological changes.