Towards a Four-Component GMMA-Based Vaccine against .

Shigellosis remains a major public health problem around the world; it is one of the leading causes of diarrhoeal disease in low- and middle-income countries, particularly in young children. The increasing reports of cases associated with anti-microbial resistance are an additional element of concern. Currently, there are no licensed vaccines widely available against , but several vaccine candidates are in development. It has been demonstrated that the incidence of disease decreases following a prior infection and that serum and mucosal antibody responses are predominantly directed against the serotype-specific O-antigen portion of lipopolysaccharide membrane molecules. Many vaccine candidates are indeed O-antigen-based. Here we present the journey towards the development of a potential low-cost four-component vaccine, eliciting broad protection against the most prevalent serotypes, that makes use of the GMMA (Generalized Modules for Membrane Antigens) technology, a novel platform based on bacterial outer membranes for delivery of the O-antigen to the immune system.