title: Antibody responses induced by Leish-Tec®, an A2-based vaccine for visceral leishmaniasis, in a heterogeneous canine population.
abstract: Zoonotic visceral leishmaniasis (VL) is a widespread disease, and dogs are the main reservoirs for human parasite transmission. Hence, development of an effective vaccine that prevents disease and reduces the transmission of VL is required. As euthanasia of seropositive dogs is recommended in Brazil for VL epidemiological control, to include anti-VL canine vaccines as a mass control measure it is necessary to characterize the humoral responses induced by vaccination and if they interfere with the reactivity of vaccinated dogs in serological diagnostic tests. Leish-Tec(®) is an amastigote-specific A2 recombinant protein vaccine against canine visceral leishmaniasis (CVL) that is commercially available in Brazil. Here, we tested the immunogenicity of Leish-Tec(®) in a heterogeneous dog population by measuring A2-specific antibody responses. Healthy dogs (n=140) of various breeds were allocated to two groups: one group received Leish-Tec(®) (n=70), and the other group received a placebo (n=70). Anti-A2 or anti-Leishmania promastigote antigen (LPA) antibody levels were measured by ELISA in serum samples collected before and after vaccination. An immunochromatographic test (DPP) based on the recombinant K28 antigen was also used for serodiagnosis of CVL. Vaccinated animals, except one, remained seronegative for anti-LPA total IgG and anti-K28 antibodies. Conversely, seropositivity for anti-A2 total IgG antibodies was found in 98% of animals after vaccination. This value decreased to 81.13% at 6 months before rising again (98%), after the vaccination boost. Anti-A2 IgG2 and IgG1 titers were also increased in vaccinated animals relative to control animals. These data indicate that Leish-Tec(®) is immunogenic for dogs of different genetic backgrounds and that humoral responses induced by vaccination can be detected by A2-ELISA, but do not interfere with the LPA-ELISA and DPP diagnostic tests for CVL.
authors.affiliation: Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors.forename: Miriam C de Souza
authors.initials: MC
authors.lastname: Testasicca
authors.affiliation: Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors.forename: Mariana Silva
authors.initials: MS
authors.lastname: dos Santos
authors.affiliation: Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors.forename: Leopoldo Marques
authors.initials: LM
authors.lastname: Machado
authors.affiliation: Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors.forename: Angela Vieira
authors.initials: AV
authors.lastname: Serufo
authors.affiliation: Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors.forename: Daniel
authors.initials: D
authors.lastname: Doro
authors.affiliation: Fundação Ezequiel Dias, Belo Horizonte, MG, Brazil.
authors.forename: Daniel
authors.initials: D
authors.lastname: Avelar
authors.affiliation: Hertape Calier Saude Animal, Juatuba, MG, Brazil.
authors.forename: Ana Maria Leonardi
authors.initials: AM
authors.lastname: Tibúrcio
authors.affiliation: Labtest Diagnostica, Belo Horizonte, MG, Brazil.
authors.forename: Christiane de Freitas
authors.initials: Cde F
authors.lastname: Abrantes
authors.affiliation: Departamento de Ciências Médicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil.
authors.forename: George Luiz Lins
authors.initials: GL
authors.lastname: Machado-Coelho
authors.affiliation: Centro de Pesquisa Gonçalo Moniz/Fiocruz, Salvador, BA, Brazil.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Grimaldi
authors.affiliation: Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil; Centro de Pesquisas René Rachou/Fiocruz, Belo Horizonte, MG, Brazil; University of Massachusetts Medical School, Worcester, MA, USA.
authors.forename: Ricardo Tostes
authors.initials: RT
authors.lastname: Gazzinelli
authors.affiliation: Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil. Electronic address: anav@uai.com.br.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Fernandes
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan / Q000276:immunology*; D004283:Dog Diseases / Q000469:parasitology / Q000517:prevention & control*; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D007074:Immunoglobulin G / Q000097:blood; D007893:Leishmania donovani / Q000276:immunology*; D054332:Leishmaniasis Vaccines / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000469:parasitology / Q000517:prevention & control*; D012698:Serologic Tests / Q000662:veterinary; D014611:Vaccination / Q000662:veterinary; D014614:Vaccines, Synthetic
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007074:Immunoglobulin G; D054332:Leishmaniasis Vaccines; D014614:Vaccines, Synthetic
keywords: A2 antigen; Antibodies; Dogs; Leish-Tec(®); Vaccine; Visceral leishmaniasis