The epidemiology of dog rabies in Algeria: Retrospective national study of dog rabies cases, determination of vaccination coverage and immune response evaluation of three commercial used vaccines

Rabies is a neglected zoonotic disease. Several animal species can transmit rabies, but domestic dogs are the main reservoir implicated in rabies transmission to human and other susceptible animals. There is a scarcity of data regarding canine rabies in Algeria. Hence, this report is the first study that attempts to understand the epidemiology of dog rabies through a retrospective national study of rabies cases between 2010 and 2016, determination of canine vaccination coverage and evaluation of immune response of three rabies commercial vaccines used in Algeria. Our results revealed the persistent nature of dog rabies in Algeria; with a mean of 131 positive cases per year. The vaccination coverage findings indicated that 30.81% (126/409) of the reported vaccinated dog and 47.98% (261/544) of all studied dogs presented low level of rabies antibodies titres (less than 0.5 IU), and were therefore considered not immune to rabies. Additionally, our vaccine evaluation findigs showed a weak immune response of inactivated vaccine without adjuvant. Even with adjuvanted inactivated and attenuated live vaccines, several vaccinated dogs did not develop vaccine protection. Therefore, our results recommend further studies to test the efficiency of adding a booster vaccine shot, especially in primo-vaccinated dogs to optimize the vaccination protocol; rabies is potentially fatal zoonosis, tolerating no vaccine failure. Moreover, the present study establish the necessity to re-examine the national rabies control program, implemented in 1996, particularly concerning population education, vaccination strategy, surveillance and campaigns monitoring.