Cyclic diadenylate monophosphate (c-di-AMP), a bacterial intracellular signaling molecule, has shown promise as an adjuvant. When delivered mucosally, c-di-AMP induces a balanced Th1/Th2 immune response, along with a Th17 response, which is vital for combating intracellular pathogens. This adjuvant achieves its effect by attracting monocytes and granulocytes, and by promoting the maturation of dendritic cells.