Validation of a Human Challenge Model Using an LT-Expressing Enterotoxigenic Strain (LSN03-016011) and Characterization of Potential Amelioration of Disease by an Investigational Oral Vaccine Candidate (VLA1701).

Controlled human infection models are important tools for the evaluation of vaccines against diseases where an appropriate correlate of protection has not been identified. Enterotoxigenic (ETEC) strain LSN03-016011/A (LSN03) is an LT enterotoxin and CS17-expressing ETEC strain useful for evaluating vaccine candidates targeting LT-expressing strains. We sought to confirm the ability of the LSN03 strain to induce moderate-to-severe diarrhea in a healthy American adult population, as well as the impact of immunization with an investigational cholera/ETEC vaccine (VLA-1701) on disease outcomes.

Beneficiary and Local Stakeholder Participation in Community-Based Nutrition Interventions.

Beneficiary and local stakeholder participation is an essential element to the success of community-based nutrition interventions. We sought to define active participation and review the available evidence on beneficiary and local stakeholder participation in community-based nutrition interventions in Africa. From reviewing the literature, we provide a reflective assessment on the process and findings.

Immune response characterization in a human challenge study with a Shigella flexneri 2a bioconjugate vaccine.

Background: Diarrheal diseases are a leading cause of global morbidity and mortality affecting all ages, but especially children under the age of five in resource-limited settings. Shigella is a leading contributor to diarrheal diseases caused by bacterial pathogens and is considered a significant antimicrobial resistance threat. While improvements in hygiene, and access to clean water help as control measures, vaccination remains one of the most viable options for significantly reducing morbidity and mortality.

Refinement of the CS6-expressing enterotoxigenic Escherichia coli strain B7A human challenge model: A randomized trial.

Background: Human challenge models for enterotoxigenic Escherichia coli (ETEC) facilitate vaccine down-selection. The B7A (O148:H28 CS6+LT+ST+) strain is important for vaccine development. We sought to refine the B7A model by identifying a dose and fasting regimen consistently inducing moderate-severe diarrhea.

Clinical endpoints in the controlled human challenge model for Shigella: A call for standardization and the development of a disease severity score.

Background: Since 1946 the controlled human infection model (CHIM) for Shigella has been used to improve understanding of disease pathogenesis, describe clinical and immunologic responses to infection and as a tool for vaccine development. As the frequency and intent for use in vaccine comparisons increases, standardization of the primary endpoint definition is necessary.

Methods: Subject-level data were obtained from previously conducted experimental Shigella CHIM studies.