Onset and duration of protective immunity against clinical disease and renal carriage in dogs provided by a bi-valent inactivated leptospirosis vaccine

J.M. Minke , R. Bey , J.P. Tronel , S. Latour , G. Colombet , J. Yvorel , C. Cariou , A.L. Guiot , V. Cozette , Biostatistician , P.M. Guigal

Protection against clinical disease and prevention of the renal carrier state remain the key objectives of vaccination against leptospirosis in the dog. In the present paper, groups of dogs were vaccinated twice with a commercial bacterin (EURICAN L) containing serovars icterohaemorrhagiae and canicola and challenged with heterologous representatives of both serovars at 2 weeks (onset of immunity) or 14 months (duration of immunity) after the second vaccination. Control dogs were not vaccinated against leptospirosis and kept with the vaccinated dogs. The challenges, irrespective of the serovar, reliably produced clinical signs consistent with infection in the control pups with up to 60% mortality. As expected clinical disease in the adult controls was less severe, but we were able to induce morbidity and mortality as well. Under these extreme challenge conditions, clinical signs in the vaccinated dogs were rare, and when observed, mild and transient in nature.

Mots clés: serovars canicola and icterohaemorrhagiae; bacterin; vaccine; clinical leptospirosis; renal carriage; onset and duration of immunity

J.M. Minke, R. Bey, J.P. Tronel, S. Latour, G. Colombet, et al.. Onset and duration of protective immunity against clinical disease and renal carriage in dogs provided by a bi-valent inactivated leptospirosis vaccine. Veterinary Microbiology, 2009, 137 (1-2), pp.137. ⟨10.1016/j.vetmic.2008.12.021⟩. ⟨hal-00485524⟩