Field randomized trial to evaluate the efficacy of the Leish-Tec ® vaccine against canine visceral leishmaniasis in an endemic area of Brazil

Regina-Silva, Shara; Feres, Ana Maria Leonardi Tibúrcio; França-Silva, João Carlos; Dias, Edelberto Santos; Michalsky, Érika Monteiro; Andrade, Hélida Monteiro de; Coelho, Eduardo Antônio Ferraz; Ribeiro, Gustavo Meirelles; Fernandes, Ana Paula; Machado-Coelho, George Luiz Lins

doi:10.1016/j.vaccine.2016.03.019

Cited by 59 publications

(36 citation statements)

References 49 publications

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“…25 vaccinated with Leish-Tec ® when compared with the placebo group (7.4% vs 17.7%), as measured by parasitological examination plus xenodiagnosis (no information was provided on clinical status in this study). However, although these authors stated that there was a reduction in transmission to sand flies from vaccinated dogs with anti-A2 positive serology, there was no statistically significant difference between the prevalence of positive sand fly pools that fed on dogs from the placebo (44.2%) and vaccinated (35.7%) groups, when they were compared independently of serology (Regina-Silva et al, 2016).…”

Section: Accepted Manuscriptmentioning

confidence: 92%

Current status and management of canine leishmaniasis in Latin America

Marcondes

Day

2019

Research in Veterinary Science

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Latin America encompasses diverse geographical, cultural and socioeconomic conditions, which are reflected in the challenges for infectious disease control in the region. One of the most significant regional infectious diseases for humans and domestic dogs is leishmaniasis, occurring as visceral leishmaniasis (VL) caused by Leishmania infantum (syn. L. chagasi) transmitted by sand flies (Lutzomyia longipalpis) and with a canine reservoir, and the more common cutaneous leishmaniasis (CL) involving multiple Leishmania spp. (particularly L. braziliensis), sand fly vectors and reservoir hosts. VL is spreading within Latin America for reasons related to mass migration of human and canine populations, with incursion into novel environments (e.g. related to deforestation) coupled with a background of poverty and poor public health infrastructure. The challenges for control of VL also include: (1) the accurate identification of infected dogs (particularly subclinically infected dogs) with the current reliance on serological rather than molecular diagnostic methods, (2) controversy surrounding the ethics and efficacy of culling of seropositive dogs, (3) the limited efficacy of currently available canine vaccines and their potential to interfere with interpretation of serological testing, (4) the expense associated with distribution of insecticidal dog collars, which may prove to be the most valuable control method, and (5) the cost and therefore accessibility of licensed medical treatment for canine leishmaniasis by the general population. Resolution of these isssues will necessitate a 'One Health' approach to coordination of resources between human and veterinary healthcare.

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Section: Accepted Manuscriptmentioning

confidence: 92%

Current status and management of canine leishmaniasis in Latin America

Marcondes

Day

2019

Research in Veterinary Science

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“…Remarkably, the vaccine was licensed without any information about efficacy in field assays. In fact, the first Phase III trial assay of Leishtec R was only published in 2016 (121). Moreover, the experiment was performed in a Brazilian endemic area with low infective pressure.…”

Section: Anti-leishmania Licensed Vaccinesmentioning

confidence: 99%

“…Moreover, the experiment was performed in a Brazilian endemic area with low infective pressure. Accordingly, the end-points of efficacy were not severe disease or deaths in canine visceral leishmaniasis, as were used for evaluation of Leishmune R previously (100, 101), but instead, seropositivity confirmed by parasitological assays alone or in combination with xenodiagnosis (121). Considering these less severe standards and based on the parasitologically positive cases, the vaccine efficacy of Leishtec R was 71.4%.…”

Section: Anti-leishmania Licensed Vaccinesmentioning

confidence: 99%

The Delay in the Licensing of Protozoal Vaccines: A Comparative History

Palatnik-de-Sousa

Nico

2020

Front. Immunol.

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“…CVL is widespread from Mexico to Argentina, with autochthonous cases reported in many countries (Marcondes & Day 2019) [EB1]. Although vaccines can prevent active infection and the risk of development of clinical disease in some dogs, some vaccinated dogs can become progressively infected and transmit the parasite to the sand fly vectors even in the absence of clinical signs (Bongiorno et al 2013, Fernandes et al 2014, Oliva et al 2014, Regina-Silva et al 2016 [EB1]. Therefore, for animals living in endemic areas, from an epidemiological viewpoint, it is more important to use insecticides, especially collars, to prevent sand fly bites, than it is to vaccinate (Sevá et al 2016, Lopes et al 2018.…”

Section: Canine Leishmaniosis In Latammentioning

confidence: 99%

“…collars) is far more important than vaccination (Sevá et al 2016, Lopes et al 2018 [EB1]. Vaccines do not produce sterilising immunity; they may prevent or lessen the severity of clinical signs in infected animals, but do not always prevent infection and so even vaccinated dogs may act as a reservoir for Leishmania (Regina- Silva et al 2016) [EB1]. Dogs should be tested before vaccination as vaccination of a dog that is already infected is of no benefit in the prevention of infection and a waste of vaccine.…”

Section: Does the Vgg Recommend Use Of A Leishmania Vaccine?mentioning

confidence: 99%

Recommendations on vaccination for Latin American small animal practitioners: a report of the WSAVA Vaccination Guidelines Group

Day

Crawford

Marcondes

et al. 2020

J of Small Animal Practice

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Executive Summary The World Small Animal Veterinary Association Vaccination Guidelines Group has produced global guidelines for small companion animal practitioners on best practice in canine and feline vaccination. Recognising that there are unique aspects of veterinary practice in certain geographical regions of the world, the Vaccination Guidelines Group undertook a regional project in Latin America between 2016 and 2019, culminating in the present document. The Vaccination Guidelines Group gathered scientific and demographic data during visits to Argentina, Brazil and Mexico, by discussion with national key opinion leaders, visiting veterinary practices and review of the scientific literature. A questionnaire survey was completed by 1390 veterinarians in five Latin American countries and the Vaccination Guidelines Group delivered continuing education at seven events attended by over 3500 veterinarians. The Vaccination Guidelines Group recognised numerous challenges in Latin America, for example: (1) lack of national oversight of the veterinary profession, (2) extraordinary growth in private veterinary schools of undetermined quality, (3) socioeconomic constraints on client engagement with preventive health care, (4) high regional prevalence of some key infectious diseases (e.g. feline leukaemia virus infection, canine visceral leishmaniosis), (5) almost complete lack of minimal antigen vaccine products as available in other markets, (6) relative lack of vaccine products with extended duration of immunity as available in other markets, (7) availability of vaccine products withdrawn from other markets (e.g. Giardia vaccine) or unique to Latin America (e.g. some Leishmania vaccines), (8) accessibility of vaccines directly by pet owners or breeders such that vaccination is not delivered under veterinary supervision, (9) limited availability of continuing education in veterinary vaccinology and lack of compulsion for continuing professional development and (10) limited peer‐reviewed published scientific data on small companion animal infectious diseases (with the exception of leishmaniosis) and lack of support for such academic research. In this document, the Vaccination Guidelines Group summarises the findings of this project and assesses in evidence‐based fashion the scientific literature pertaining to companion animal vaccine‐preventable diseases in Latin America. The Vaccination Guidelines Group makes some recommendations on undergraduate and postgraduate education and academic research. Recognising that current product availability in Latin America does not permit veterinarians in these countries to vaccinate according to the global World Small Animal Veterinary Association guidelines, the Vaccination Guidelines Group makes a series of “pragmatic” recommendations as to what might be currently achievable, and a series of “aspirational” recommendations as to what might be desirable for the future. The concept of “vaccine husbandry” is addressed via some simple guidelines for the management of vaccine products i...

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Field randomized trial to evaluate the efficacy of the Leish-Tec ® vaccine against canine visceral leishmaniasis in an endemic area of Brazil

Cited by 59 publications

References 49 publications

Current status and management of canine leishmaniasis in Latin America

Current status and management of canine leishmaniasis in Latin America

The Delay in the Licensing of Protozoal Vaccines: A Comparative History

Recommendations on vaccination for Latin American small animal practitioners: a report of the WSAVA Vaccination Guidelines Group

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