Vaccines for Canine Leishmaniasis

Abstract

Leishmaniasis is the third most important vector-borne disease worldwide. Visceral leishmaniasis (VL) is a severe and frequently lethal protozoan disease of increasing incidence and severity due to infected human and dog migration, new geographical distribution of the insect due to global warming, coinfection with immunosuppressive diseases, and poverty. The disease is an anthroponosis in India and Central Africa and a canid zoonosis (ZVL) in the Americas, the Middle East, Central Asia, China, and the Mediterranean. The ZVL epidemic has been controlled by one or more measures including the culling of infected dogs, treatment of human cases, and insecticidal treatment of homes and dogs. However, the use of vaccines is considered the most cost–effective control tool for human and canine disease. Since the severity of the disease is related to the generation of T-cell immunosuppression, effective vaccines should be capable of sustaining or enhancing the T-cell immunity. In this review we summarize the clinical and parasitological characteristics of ZVL with special focus on the cellular and humoral canine immune response and review state-of-the-art vaccine development against human and canine VL. Experimental vaccination against leishmaniasis has evolved from the practice of leishmanization with living parasites to vaccination with crude lysates, native parasite extracts to recombinant and DNA vaccination. Although more than 30 defined vaccines have been studied in laboratory models no human formulation has been licensed so far; however three second-generation canine vaccines have already been registered. As expected for a zoonotic disease, the recent preventive vaccination of dogs in Brazil has led to a reduction in the incidence of canine and human disease. The recent identification of several Leishmania proteins with T-cell epitopes anticipates development of a multiprotein vaccine that will be capable of protecting both humans and dogs against VL.

Resistance to visceral leishmaniasis is severely compromised in mice deficient of bradykinin B2-receptors

“…Furthermore, the decrease in DTH response against leishmanial antigen was negatively correlated to the increase in liver/ body relative weight (R = −0.5003; p = 0.025) (Figure 3B). Since DTH is a strong correlate of protection and required for optimal development of resistance to VL [27-30], we may infer that the impaired DTH observed in KOB2 mice is an expression of deficient cellular immunity.…”

Avaliação da infectividade parasitária a Lutzomyia longipalpis por xenodiagnóstico em cães tratados para leishmaniose visceral naturalmente adquirida

“…Diferentes estudos apontam medidas mais eficazes que a eutanásia para o controle e prevenção da LV, como o uso de coleiras impregnadas com inseticidas, vacinação e tratamento dos cães infectados (Reithinger et al 2004, Solano-Gallego et al 2009, Maroli et al 2010, Palatnik-de-Sousa 2012, Fernandes et al 2014. Na Europa, e em todos os países onde a LV é endêmica, a eutanásia de cães soropositivos não é utilizada como medida de controle da doença e os cães infectados são rotineiramente tratados (Gradoni et al 1987, Alvar et al 1994, Solano-Gallego et al 2009, Solano-Gallego et al 2011.…”

Leishmaniasis: Epidemiology, Control and Future Perspectives with Special Emphasis on Egypt

“…It is composed of fusion of the three relatively conserved L. major proteins that is formulated with MPL-SE. Nonetheless, there is no single vaccine that is licensed for prophylaxis against VL in human [42]. In 2013, Guha et al demonstrated the potential of hemoglobin receptor (HbR) as a vaccine candidate against visceral leishmaniasis where they found that HbR is conserved across various strains of Leishmania and can potentially induce a complete protection against virulent Leishmania donovani infection challenges in both mice and hamsters [43].…”