[Persistence of serologic and allergic reactions in ewes after vaccination with the H.38 or Rev.1 vaccines in a brucellosis (Brucella melitensis) enzootic area].

In a flock of 2,000 ewes located in an endemic area of Brucella melitensis infection, subjected to systematic vaccination of lambs either with killed and adjuvanted B. melitensis H.38 vaccine from 1973 to 1978, or with living B. melitensis Rev.1 vaccine since 1979, reactions to allergic intrapalpebral test, complement fixation test and Rose Bengal plate test were recorded in small groups of animals vaccinated four, three, two or one years ago. Four years after H.38 vaccination, 39 ewes out of 40 (97%) remained positive at least to one of the three tests. After vaccination with strain Rev.1, 16% out of 153 ewes vaccinated one to four years before were positive. These results were discussed according to two aspects: 1) infectious or vaccinal origins of these positive reactions; 2) consequences on implement of test and slaughter procedures in a vaccinated flock: allergic or complement fixation tests would have led to eliminate 9% out of ewes vaccinated with the Rev.1 vaccine, but only 1% with the Rose Bengal plate test.