Jacobs Journal of Vaccines and Vaccination

Efficacy of DAPPi2 -LR Canine Vaccine against Rabies and Leptospira Induced Clinical Signs, Mortality and Renal Carriage

*Dr. Lionel Cupillard
Department Of Vaccines And Vaccinations, France

*Corresponding Author:
Dr. Lionel Cupillard
Department Of Vaccines And Vaccinations, France
Email:Lionel.Cupillard@merial.com

Published on: 2018-12-28

Abstract

Efficacy of the Leptospiral and rabies components of EURICAN DAPPi2 -LR, a canine combined vaccine, was demonstrated after a primary course of vaccination using one dose of EURICAN® DAPPi2 -L followed by one dose of EURICAN® DAPPi2 -LR. Challenges for leptospirosis (serovars Canicola and Icterohaemorrhagiae) were carried out in puppies 14 days after vaccination for the onset of immunity studies (OOI), in adults 13/14 months after vaccination for the duration of immunity studies (DOI), and for rabies in adults 13 months after vaccination. For OOIs, vaccination provided full clinical protection against severe Leptospira challenges and prevented renal carriage and detectable excretion of Leptospira in urine. For DOIs, clinical signs of leptospirosis were less severe in controls but were absent or mild and transient in vaccinated dogs, and urinary shedding was significantly reduced (frequency and duration). In addition, a single dose of EURICAN® DAPPi2 -LR induced rabies virus neutralizing antibodies in all dogs as early as 2 weeks post-vaccination and provided full protection in a rabies challenge performed after 13 months. Vaccine has a high efficacy profile with a quick onset of immunity as early as 2 weeks post vaccination, providing full protection against fatal leptospirosis caused by L. Canicola and L. Icterohaemorrhagiae and strong seroconversion against rabies. Long-term protection was also demonstrated by challenges performed 13/14 months post vaccination with reduction of mortality, clinical signs, infection, renal carriage, and bacterial excretion for Leptospira and protection against mortality and clinical signs for rabies.

Keywords

Leptospira Canicola; Icterohaemorrhagiae; Rabies; Vaccine; Onset and Duration Of Immunity; Challenge

Introduction

Leptospirosis is the most widespread zoonotic disease in the world, affecting a broad range of mammals. It is caused by infection with pathogenic Leptospira species [1]. Clinical signs associated with Leptospira infection in dogs range from subclinical infection to acute disease. Common features include anorexia, vomiting, lethargy, muscle pain, dehydration, jaundice, abdominal pain, diarrhoea, bloody urine, and death [1- 6]. Acute renal failure is the predominant finding in symptomatic dogs, alone or associated with signs of hepatic injury [2, 3 6, 7]. Animals recovering from leptospirosis may become asymptomatic carriers harbouring virulent leptospires in the renal tubules for extended periods and shedding infectious leptospires into the environment, thus being a possible source of human leptospirosis [1,7]. Excretion in urine may be intermittent or continuous and the urinary concentration of bacteria may be high [1,4,5]. Infection of naï?ve ani - mals results from contact of intact mucous membranes, such as ocular conjunctival, or abraded skin with infected urine or urine-contaminated soil, water, food, or bedding [1,4]. Humans are incidental hosts and usually become infected through occupational, recreational or domestic contact with the urine of carrier animals (such as the dog), either directly or via contaminated water or soil.