Vaccination as the new control tool

The development of an effective and safe vaccine against canine Leishmaniasis has been identified as a key point in the control of the disease.

Firstly, because a vaccine of these characteristics would reduce the canine disease and consequently the human disease. Secondly, because it would probably be the most cost-effective strategy. Finally, a vaccine against canine Leishmaniasis could serve as a pilot test for developing an effective vaccine against human Leishmaniasis. Dogs are considered the most suitable model in order to understand Leishmaniasis in humans (Alvar, 2004).

An ideal vaccine for canine Leishmaniasis should:

  1. induce a long-lasting immune response which fully protects dogs from the disease developing.
  2. be safe, both in the short and long term (after booster vaccinations).

One point that has aroused much interest is whether the vaccination offers protection against infection or only against the development of clinical signs. All the data appears to indicate that the current vaccines do not prevent infection but simply prevent the progression of a subclinical infection to a symptomatic infection. In this sense, the vaccinated dogs behave like infected dogs that spontaneously control the infection and remain free of clinical signs. As well as the obvious importance for vaccinated animals, this point has an impact on the epidemiology of the disease, since infected dogs without clinical signs present a much lower parasite load and so play a smaller role in the transmission of the disease. In short, although obtaining a vaccine that protects against infection (sterilising vaccine) is a mid-term objective, the current vaccines should be considered useful instruments in controlling the disease, both in the individual dog and in the community. Indeed, this was recognised in the recent EFSA (European Food Safety Authority) report, which indicates that vaccination together with the use of insecticides are the most suitable instruments for controlling the epidemic in Europe and that the two measures are complementary and not alternatives (EFSA, 2016)

LETI has developed LetiFend®, the first vaccine against canine Leishmaniasis developed in Europe with a chimeric protein, and it provides veterinarians with a totally safe tool.