Human leishmaniasis vaccines: Use cases, target population and potential global demand.

The development of vaccines against one or all forms of human leishmaniasis remains hampered by a paucity of investment, at least in part resulting from the lack of well-evidenced and agreed estimates of vaccine demand. Starting from the definition of 4 main use cases (prevention of visceral leishmaniasis, prevention of cutaneous leishmaniasis, prevention of post-kala-azar dermal leishmaniasis and treatment of post-kala-azar dermal leishmaniasis), we have estimated the size of each target population, focusing on those endemic countries where incidence levels are sufficiently high to justify decisions to adopt a vaccine. We assumed a dual vaccine delivery strategy, including a wide age-range catch-up campaign before the start of routine immunisation. Vaccine characteristics and delivery parameters reflective of a target product profile and the likely duration of the clinical development effort were considered in forecasting the demand for each of the four indications. Over a period of 10 years, this demand is forecasted to range from 300-830 million doses for a vaccine preventing visceral leishmaniasis and 557-1400 million doses for a vaccine preventing cutaneous leishmaniasis under the different scenarios we simulated. In a scenario with an effective prophylactic visceral leishmaniasis vaccine, demand for use to prevent or treat post-kala-azar dermal leishmaniasis would be more limited (over the 10 years ~160,000 doses for prevention and ~7,000 doses for treatment). Demand would rise to exceed 330,000 doses, however, in the absence of an effective vaccine for visceral leishmaniasis. Because of the sizeable demand and potential for public health impact, a single-indication prophylactic vaccine for visceral or cutaneous leishmaniasis, and even more so a cross-protective prophylactic vaccine could attract the interest of commercial developers. Continuous refinement of these first-of-their kind estimates and confirmation of country willingness and ability to pay will be paramount to inform the decisions of policy makers and developers in relation to a leishmaniasis vaccine. Positive decisions can provide a much-needed contribution towards the achievement of global leishmaniasis control.

Leishmaniasis / No disponible

La leishmaniasis es una enfermedad parasitaria causada por parásitos protozoarios del género Leishmania, transmitidos por la picadura de insectos flebotomineos hematófagos que se han alimentado previamente en un hospedero reservorio infectado. Existen dos presentaciones clínicas básicas: leishmaniasis visceral (LV) o “kala-azar” y leishmaniasis cutánea (LC). VL es el más grave y es mortal en casi todos los casos si no se tratan oportunamente, mientras que CL se asocia con una fuerte tendencia hacia la resolución espontánea, pero causa estigma social y psicológico importante en las personas afectadas. La leishmaniasis es una problema de salud pública importante en muchos regiones del mundo. A pesar de los avances de la ciencia básica, la leishmaniasis sigue siendo prevalente (y de aparición reciente) en muchas partes del mundo y el tratamiento eficaz y la prevención de la enfermedad sigue siendo un desafío. Se requieren nuevos tratamientos farmacológicos, especialmente aquellos que pueden ser de fácil administración y bajo costo. Así mismo, se requiere que la investigación en vacunas avance lo más rápidamente posible desde los estudios pre-clínicos a los estudios clínicos. Esta revisión destaca los aspectos más importantes en el estudio del parásito de la leishmaniasis en relación con la biología y la taxonomía, el ciclo de la vida y la patogénesis de la enfermedad, la respuesta inmune, las formas clínicas de la leishmaniasis, el diagnóstico, el tratamiento y las medidas de prevención (AU)

Leishmaniasis is a parasitic disease caused by protozoan parasites of the genus Leishmania, transmitted by the bite of blood suckling insects, sandflies, which have previously fe don an infected reservoir host. There are two basic clinical presentations: visceral leishmaniasis (VL) or “kala-azar” and cutaneous leishmaniasis (CL). VL is the most severe and is fatal in almost all cases if left untreated, while CL is associated with a strong tendency toward spontaneous resolutionbut causes important social and psychological stigma. The leishmaniaiss is a significant remains prevalent (and newly emerging) in many parts of the world, and the effective treatment and prevention of disease continues to be a challenge. New drug therapies, especially those that can be easily and inexpensively administered are needed. Vaccine research must move as quickly as possible form pre-clinical to clinical studies. This review highlights the most important aspects in the study of leishmaniasis related to parasite biology and taxonomy , life cycle and disease pathogenesis, immune response, clinical aspects, diagnosis treatment and prevention (AU)