A phase III trial of efficacy of the FML-vaccine against canine kala-azar in an endemic area of Brazil (Sao Goncalo do Amaranto, RN)

Protection against canine kala-azar was investigated in naturally exposed d ogs of an endemic area, vaccinated with the fucose mannose ligand (FML)-vac cine of Leishmania donovani. A total of 97% of vaccinees were seropositive to FML and 100% showed intradermal reaction to L. donovani lysate, 7 months after vaccination. The absorbency values and size of intradermal reaction were both significantly higher in vaccinees than in controls (ANOVA, P < 0. 0001). After 2 years, 92% (<chi>(2) = 6.996; P < 0.0025) protection was ach ieved: only 8% of vaccinees showed mild signs of kala-azar with no deaths w hile 33% of controls developed clinical or fatal disease. The FML-vaccine i nduced a significant, long-lasting and strong protective effect against can ine kala-azar in the field. (C) 2000 Elsevier Science Ltd. All rights reser ved.