A team of researchers from the departments of Microbiology and Pharmaceutical Technology of the Universidad of Navarra worked on the development of a new oral vaccine in order to treat bacterial dysentery, or shigellosis. This pathology causes 1.1 million deaths per year around the world; 61% of deaths occur among children under 5 years of age.
The disease, produced by the Shigella bacteria—a group of pathogens which cause bacterial dysentery—provoke a severe process of diarrhea. The path of infection is fecal-oral, with the peculiarity that a only a small infective dosage is sufficient to contract the illness. Thus, shigelosis affects 164.7 million persons around the world, 163.2 million in developing countries and 1.5 million in industrialized countries.
“Therefore”, noted Prof. Carlos Gamazo, coordinator of the project in the area of Microbiology of the University of Navarra, “the WHO has given priority to programs for the development of vaccines effective against this disease, since the implementation of preventive measures of a hygienic-sanitary type presents a great difficulty, and, on the other hand, we are observing a high prevalence of strains which are multi-resistant to antibiotics”.
In addition, the specialist confirmed that none of the existing vaccines have had important success in prior trials, and some of them, which are attenuated vaccines, cause symptoms of diarrhea and fever which limit their use in humans.
A safer treatment
In the case of the new treatment developed by the scientists of the University of Navarra, the vaccine is safer thanks to the use of subcellular fractions based on nanoparticles which permit their administration via the mucous membranes. In fact, Ana Camacho, first author of the article, confirms that up to now “the vaccine has been applied only in murine models (mice), but with a 100% success rate in preventing experimental infections”.
The project brings together teams from the departments of Microbiology and Pharmaceutical Technology. The first of these, coordinated by Carlos Gamazo, is in charge of the selection of adequate vaccine antigens and the tracking of the induced immune response. The second, on the other hand, with Dr. Juan Manuel Irache at its head, develops the appropriate nanoparticulate formulation which facilitates the administration of the vaccine.
In addition to these two researchers, the authors of the article are Ana Camacho, Juliana de Souza, Patricia Ojer, Susana Sánchez and Adela López de Cerain. The project obtained the first prize at Microbiotec’ 11, an encounter concerning Biotechnology held in Braga (Portugal), and has received recognition at two international congresses held in Prague (Czech Republic) and Baltimore (USA).