The development and licensure of a safe and highly efficacious Shigella vaccine has been a priority in international public health circles for decades and would represent a great scientific achievement. Nonetheless, in the context of increasingly crowded and costly childhood immunization programs, and with a myriad of other new and improved vaccines currently or soon on the market, there is no guarantee that even a highly effective Shigella vaccine would become a priority for adoption and introduction by the low- and middle-income countries that could benefit from it the most. We discuss here some of the major determinants and questions regarding the introduction of Shigella vaccines and the importance of developing a succinct, compelling public health value proposition.