Study on the efficacy of Leptospira vaccines developed from serovars isolated from Trinidad and comparison with commercial vaccines using a hamster model.
A hamster model was used to determine the efficacy of commercially prepared canine vaccines against Leptospira serovars circulating in Trinidad and to assess the effectiveness of killed whole-cell vaccines prepared from local isolates. The local isolates used for vaccine preparation and challenge were isolates of serovars Copenhageni and Mankarso obtained from a local dog and rodent. Their estimated lethal dose-50 (LD(50)) were 5 and 10 organisms, respectively and clinical signs observed on infection were consistent with leptospirosis. An unvaccinated control group of hamsters and other groups of hamsters that had been vaccinated with 3 doses of (i) in-house whole-cell Copenhageni vaccine, (ii) in-house whole-cell Mankarso vaccine, (iii) commercial vaccine Brand A or (iv) commercial vaccines Brand B were challenged with 1000 times the LD(50) of the respective challenge serovar. The most commonly used commercial vaccine (Brand A) did not offer protection to challenged hamsters, whereas Brand B facilitated the renal carrier state of the Leptospira organism. In contrast the whole-cell vaccines developed from local strains of serovars Copenhageni and Mankarso, protected all hamsters tested from both clinical disease and renal carrier states.
Suepaul
S M
SM
School of Veterinary Medicine, Faculty of Medical Sciences, University of The West Indies, St. Augustine, Trinidad and Tobago.
Carrington
C V
CV
Campbell
M
M
Borde
G
G
Adesiyun
A A
AA
D000818:Animals; D001428:Bacterial Vaccines / Q000276:immunology / Q000494:pharmacology*; D006224:Cricetinae; D004283:Dog Diseases / Q000276:immunology / Q000517:prevention & control; D004285:Dogs; D004306:Dose-Response Relationship, Immunologic; D007919:Leptospira / Q000276:immunology* / Q000302:isolation & purification*; D007922:Leptospirosis / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary; D008647:Mesocricetus; D018448:Models, Immunological; D013045:Species Specificity; D014300:Trinidad and Tobago
D001428:Bacterial Vaccines