Shigellosis (which leads to diarrhea, and often dysentery) is a wretched disease, and if you're here, you probably followed along my live-tweeting of my experience with it in the clinical trial setting. Even if the experimental vaccine is successful, it will not be a panacea. Shigella is easily transmitted in places that lack adequate public sanitation. That overwhelmingly tends to be in the developing world. For children who contract the disease, there is often measurable impact on their development and growth, and, of course, the threat of a very painful death.
Having had this absolutely awful disease — and recovered fairly quickly, thanks to access to medical care — I really, really would like to use my fifteen minutes of Twitter fame to help prevent it elsewhere.