Comparison of the efficacy of three commercial bacterins in preventing canine leptospirosis

Abstract

Twenty‐four specific pathogen‐free beagles were randomly allocated into four groups (three vaccinated groups and one control group) and inoculated at nine and 12 weeks of age with one of three commercial inactivated Leptospira vaccines: A (Vanguard 7; Pfizer Santé Animale), B (Dohyvac 7L; Fort Dodge), and C (Nobivac DHPPi + Lepto; Intervet Intemational); the control group received Nobivac DHPPi (Intervet International). Seven weeks after the second vaccination all the dogs were challenged with Leptospira interrogans serogroup canicola. All the vaccinated dogs developed a mild serological response (microscopic agglutination titres) after the booster vaccination. A significant serological response after the challenge was observed, particularly in the controls. The challenge induced fever and clinical disorders in the control group, whereas in the vaccinated groups the clinical signs were mild. Blood cultures became positive in all control dogs, and in one of six dogs vaccinated with vaccine A and two of four dogs vaccinated with vaccine B; none of the six dogs vaccinated with vaccine C was leptospiraemic at any stage of the experiment. Urine cultures were positive in all the control dogs two weeks after the challenge. One of six dogs vaccinated with vaccine A and two of four dogs vaccinated with vaccine B shed bacteria in their urine after the challenge, but none of the dogs vaccinated with vaccine C shed bacteria in their urine at any time during the experiment.

Protection of Guinea Pigs against Leptospira interrogans Serovar Lai by LipL21 DNA Vaccine

“…The current available vaccines based on inactivated whole bacteria or membrane preparations from pathogenic leptospires have shown some drawbacks. These include very low efficacy, an unacceptable side-effect profile, the requirement for annual booster immunizations, and failure to confer cross-protective immunity against different serovars (2,5,17). Generally, however, these vaccines do provide protection against the lethal onset of the disease, although they do not prevent persistent shedding from infected humans and animals (18).…”

Protection againstLeptospira interrogansSensu Lato Challenge by DNA Immunization with the Gene Encoding Hemolysin-Associated Protein 1

“…Finally, the plates were washed five times, and the chromogenic substrate 3,3Ј-5,5Ј-tetramethylbenzidine was added. After 10 min, the reaction was stopped by adding 2 M H 2 SO 4 Fig. 1.…”

“…These bacterins therefore provide no cross-protection against the different serogroups of pathogenic leptospires (53). However, these vaccines do generally provide protection against lethal onset of the disease, but they do not prevent persistent shedding from infected animals (1,4).…”

Immunoprotection of Recombinant Leptospiral Immunoglobulin-Like Protein A against Leptospira interrogans Serovar Pomona Infection

“…Prevention of leptospirosis in dogs is accomplished to some extent by inoculation with bacterins that contain the most commonly encountered serovars. Although leptospiral bacterins may protect dogs from developing clinical signs of the disease, they are ineffective in preventing leptospiremia and renal shedding (2). In contrast, a monovalent leptospiral vaccine can prevent renal colonization and urinary shedding in cattle challenged with Leptospira borgpetersenii serovar Hardjo, but with minor interstitial nephritis (4).…”