immune responses of goats (shami breed) to vaccination with a full, reduced and conjunctival dose of brucevac (brucella melitensis rev.1) vaccine

Three groups of Shami goats were randomly vaccinated with Brucevac (Rev. 1) vaccine. Group 1 was vaccinated subcutaneously with a full dose (1.54 x 109 organisms). Group 2 was vaccinated conjunctively with one eye drop (5.2 x 108 organisms), while Group 3 was injected subcutaneously with a reduced dose (7.1 x 105 organisms) of vaccine. Blood samples were collected before vaccination, two, four, eight, 15 and 24 weeks post vaccination. All samples were tested through CFT, ELISA, SAT and Rose Bengal plate test. All serological tests used detected a higher percentage of vaccinated female kids with a full dose than they did in other groups vaccinated with a reduced dose or with a conjunctival dose of Rev.1 vaccine. The overall results suggested that 100% of animals vaccinated with a conjunctival dose became positive to CFT at two, four, eight and 15 weeks post vaccination, and then the percentage of seropositive animals declined and became 20% at 24 weeks post inoculation. The conjunctival route of vaccination significantly reduced the intensity and duration of the post vaccination serological response, which makes the use of this vaccine compatible with brucellosis programmes, even when these are based on a test-and–slaughter policy. The overall results showed that Shami goats responded to Rev.1 vaccine in the expected way. The majority of animals were seropositive to the CFT by two weeks after vaccination with higher numbers of seropositive animals in the kids group vaccinated with a full dose of Rev.1 vaccine.