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Based on prevalence and impact on public health, toxocariasis is an underestimated zoonosis in developing and developed countries. The transmission of Toxocara spp. involves pets, stray dogs and cats (Canis familiaris and Felis catus, respectively), which spread the parasite’s eggs in their feces to the environment. One of the main risk factors for the infection and development of human toxocariasis, is to cohabit with puppies and kittens. For a long time, the preventive strategy for this parasitic infection has been the regular use of antiparasitic drugs to reduce parasite burden in the short term. A long lasting immunological protection can be achieved with vaccination, however, a vaccine is not yet available. Therefore, it is fundamental to know and to understand the state of the art of vaccine development for effective control of this zoonosis. This paper reviews the experimental studies focused on vaccine development for toxocariasis control, and special attention is given to relevant epidemiological studies on the importance of dogs in human toxocariasis. Resumen Según la prevalencia y el impacto en la salud pública, la toxocariasis es una zoonosis subestimada en los países en desarrollo y desarrollados. La transmisión de Toxocara spp. involucra animales de compañía caninos y felinos, como también perros y gatos sin hogar (Canis familiaris y Felis catus, respectivamente), que diseminan los huevos del parásito en sus heces al medio ambiente. Uno de los principales factores de riesgo para la infección y el desarrollo de la toxocariasis humana es convivir con cachorros felinos y caninos. Durante mucho tiempo, la estrategia preventiva para esta infección parasitaria ha sido el uso regular de medicamentos antiparasitarios para reducir la carga parasitaria a corto plazo. Se puede lograr una protección inmunológica duradera con la vacunación, sin embargo, todavía no se dispone de una vacuna. Por lo tanto, es fundamental conocer y comprender el estado del arte del desarrollo de vacunas para el control efectivo de esta zoonosis. Este artículo revisa los estudios experimentales centrados en el desarrollo de vacunas para el control de la toxocariasis, y se presta especial atención a los estudios epidemiológicos relevantes sobre la importancia de los caninos domésticos en la toxocariasis humana. Resumo Com base na prevalência e no impacto na saúde pública, a toxocaríase é uma zoonose subestimada nos países em desenvolvimento e desenvolvidos. A transmissão de Toxocara spp. envolve animais cães e gatos de estimação e vadios (Canis familiaris e Felis catus, respectivamente), que espalham os ovos do parasita nas fezes para o meio ambiente. Um dos principais fatores de risco para a infecção e desenvolvimento da toxocaríase humana é coabitar com filhotes de cachorros e gatos. Por um longo tempo, a estratégia preventiva para essa infecção parasitária tem sido o uso regular de medicamentos antiparasitários para reduzir a carga parasitária a curto prazo. Uma proteção imunológica duradoura pode ser alcançada com a vacinação, no entanto, uma vacina ainda não está disponível. Portanto, é fundamental conhecer e entender o estado da arte do desenvolvimento de vacinas para o controle efetivo dessa zoonose. Este artigo revisa os estudos experimentais focados no desenvolvimento de vacinas para o controle da toxocaríase, e atenção especial é dada a estudos epidemiológicos relevantes sobre a importância dos cães na toxocaríase humana.

Introduction Allergenspecific immunotherapy (AIT) represents a curative approach for treating allergies. In the tropical and subtropical regions of the world, Blomia tropicalis (Blo t 5 and Blo t 21) is the likely dominant source of indoor allergens. Aim To generate a hypoallergenic Blo t 5/Blo t 21 hybrid molecule that can treat allergies caused by B tropicalis. Methods Using in silico design of B tropicalis hybrid proteins, we chose two hybrid proteins for heterologous expression. Wildtype Blo t 5/Blo t 21 hybrid molecule and a hypoallergenic version, termed BTH1 and BTH2, respectively, were purified by ion exchange and size exclusion chromatography and characterized by physicochemical, as well as in vitro and in vivo immunological, experiments. Results BTH1, BTH2 and the parental allergens were purified to homogeneity and characterized in detail. BTH2 displayed the lowest IgE reactivity that induced basophil degranulation using sera from allergic rhinitis and asthmatic patients. BTH2 essentially presented the same endolysosomal degradation pattern as the shortened rBlo t 5 and showed a higher resistance towards degradation than the fulllength Blo t 5. In vivo immunization of mice with BTH2 led to the production of IgG antibodies that competed with human IgE for allergen binding. Stimulation of splenocytes from BTH2immunized mice produced higher levels of IL10 and decreased secretion of IL4 and IL5. In addition, BTH2 stimulated Tcell proliferation in PBMCs isolated from allergic patients, with secretion of higher levels of IL10 and lower levels of IL5 and IL13, when compared to parental allergens. Conclusions and Clinical Relevance BTH2 is a promising hybrid vaccine candidate for immunotherapy of Blomia allergy. However, further preclinical studies addressing its efficacy and safety are needed. (VLID)5815269