title: Comparative evaluation of phenol and thimerosal as preservatives for a candidate vaccine against American cutaneous leishmaniasis.
abstract: For decades thimerosal has been used as a preservative in the candidate vaccine for cutaneous leishmaniasis, which was developed by Mayrink et al. The use of thimerosal in humans has been banned due to its mercury content. This study addresses the standardization of phenol as a new candidate vaccine preservative. We have found that the proteolytic activity was abolished when the test was conducted using the candidate vaccine added to merthiolate (MtVac) as well as to phenol (PhVac). The Montenegro's skin test conversion rates induced by MtVac and by PhVac was 68.06% and 85.9%, respectively, and these values were statistically significant (p < 0.05). The proliferative response of peripheral mononuclear blood cells shows that the stimulation index of mice immunized with both candidate vaccines was higher than the one in control animals (p < 0.05). The ability of the candidate vaccines to induce protection in C57BL/10 mice against a challenge with infective Leishmania amazonensis promastigotes was tested and the mice immunized with PhVac developed smaller lesions than the mice immunized with MtVac. Electrophoresis of phenol-preserved antigen revealed a number of proteins, which were better preserved in PhVac. These results do in fact encourage the use of phenol for preserving the immunogenic and biochemical properties of the candidate vaccine for cutaneous leishmaniasis.
authors.affiliation: Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil.
authors.forename: Wilson
authors.initials: W
authors.lastname: Mayrink
authors.forename: Carlos Alberto Pereira
authors.initials: CA
authors.lastname: Tavares
authors.forename: Rosangela Barbosa de
authors.initials: RB
authors.lastname: Deus
authors.forename: Melina Barros
authors.initials: MB
authors.lastname: Pinheiro
authors.forename: Tânia Mara Pinto Dabés
authors.initials: TM
authors.lastname: Guimarães
authors.forename: Hélida Monteiro de
authors.initials: HM
authors.lastname: Andrade
authors.forename: Carlos Alberto da
authors.initials: CA
authors.lastname: Costa
authors.forename: Vicente de Paulo Coelho Peixoto da
authors.initials: Vde P
authors.lastname: Toledo
mesh_terms: D000328:Adult; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D006801:Humans; D054332:Leishmaniasis Vaccines / Q000737:chemistry* / Q000276:immunology; D016773:Leishmaniasis, Cutaneous / Q000517:prevention & control*; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D019800:Phenol / Q000009:adverse effects / Q000592:standards*; D011310:Preservatives, Pharmaceutical / Q000009:adverse effects / Q000592:standards*; D012882:Skin Tests; D013849:Thimerosal / Q000009:adverse effects / Q000592:standards*
chemical_list: D054332:Leishmaniasis Vaccines; D011310:Preservatives, Pharmaceutical; D013849:Thimerosal; D019800:Phenol