Resumen

SOSA ROBLE, Eligio et al. Local tolerance study of vax-TyVi® vaccine in Sprague Dawley rats . Vaccimonitor [online]. 2005, vol.14, n.1, pp.21-27. ISSN 1025-028X.

The anti-typhoid vaccine vax-TyVi® consists in the Vi capsular polysaccharide of Salmonella typhi, which is diluted in an isotonic buffer solution with phenol as a preservative. Each dose of 0,5 mL contains 25μg of polysaccharide as an active component. The vaccination schedule in Cuba against typhoid fever includes the application of vax-TyVi® to 9-10 year-old students (5th grade, primary school), a second dose for 12-15 year-olds (8th grade, secondary school ) and the third dose for 16-17 year-olds (11th grade). The high-risk population is additionally immunized. The present work describes the local tolerance assay undertaken for vax-TyVi® as part of its preclinical safety studies. A total of 170 rats were treated with either the vaccine, the placebo (all components, but the active ingredient) or were not treated and served as controls. Clinical observations were made daily during the whole study. Water and food intakes were measured and anatomopathological studies were conducted on animals that were sacrificed 3, 7, 14, 21, 28, 35 and 42 days after the inoculation. No animal died or showed symptoms of toxicity. Body weight and the intakes of food and water were statistically similar in the three experimental groups and there were no tissue changes indicative of local or systemic toxicity. Results suggest that vax-TyVi® is potentially innocuous at the inoculation site.

Palabras clave : Toxicology; Local Tolerance Test; vax-TyVi®,; rats.

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