A set of immune assays will be established to determine the immune response after ShigETEC vaccination (Phase 1a and b clinical trials) and after natural exposure to Shigella and ETEC. Among others, these assays will allow to assess antibody responses on a global scale, to determine the functionality of induced antibodies, to determine antibody affinity and avidity, to distinguish between pre-existing immunity and true vaccine induced antibody responses and to compare vaccine-induced antibody responses in adults and children. 

 

In order to study the natural immune responses to Shigella and ETEC in adults and children, about 2000 patients presenting with mucoid or watery stool to icddr.b Dhaka Hospital and health facilities in Mirpur (area in the North of Dhaka, Bangladesh) will be enrolled in the seroepidemiology study. Stool and blood samples will be collected at different days after confirmation of Shigella and ETEC infection.  

 

Similarly, blood and stool samples will be collected at different days post-ShigETEC vaccination during Phase 1a and 1b clinical trials in Europe and Bangladesh. The evaluation of immune response after Phase 1 clinical trials will allow to define the most effective vaccination schedule for future clinical testing (Phase 2 clinical trial).