Field Trials of Attenuated Salmonella Typhi Live Oral Vaccine TY21A in Liquid and Enteric-Coated Capsule Formulations in Santiago, Chile

Abstract

In a randomized, double-blind, controlled field trial in Santiago, Chile, 81,621 school-children, 5-19 years of age, received three doses, within one week, of attenuated Salmonella typhi oral vaccine Ty21a in enteric-coated capsules or in a new liquid suspension, or placebo. Over 36 months of surveillance, the liquid formulation (76.9% vaccine efficacy) was markedly superior to enteric-coated capsules (33.2% vaccine efficacy) (p=0.0000077). The liquid formulation protected young children (5-9 years old) (vaccine efficacy 82.3%) as well as older children > or = 10 years) (69.3% vaccine efficacy), while the capsules significantly protected only older children. The liquid suspension was practical to prepare by mixing lyophilized vaccine with buffer in water and was easily administered, even to the youngest children. It was concluded that the liquid formulation of Ty21a is preferable to enteric-coated capsules.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1990
Accession Number
ADA228864

Entities

People

  • Catterine Ferreccio
  • Myron M. Levine
  • Valeria Prado

Organizations

  • University of Maryland School of Medicine

Tags

DTIC Thesaurus Topics

  • Acids
  • Bile
  • Classification
  • Diseases And Disorders
  • Gram-Negative Bacterial Infections
  • Health
  • Health Care
  • Health Services
  • Immunization
  • Inclusions
  • Materials
  • Medical Personnel
  • Oral Vaccines
  • Public Health
  • Security
  • Surveillance
  • Vaccination

Readers

  • Gender and Food Studies
  • Microbial Pathology
  • Virology (or Medical Virology).

Technology Areas

  • Biotechnology