Abstract: Nanoparticles for providing immune responses for the treatment or prophylaxis of infection by infectious agents such as viruses, parasites, bacteria, prions and fungi are described which comprises a core including metal and/or semiconductor atoms, wherein the core is covalently linked to a plurality of ligands, the ligands including a carbohydrate residue capable of stimulating an innate immune response, a T cell helper peptide and a danger signal. This platform may then be adapted by including one or more further ligands capable of producing a specific response to a target infectious agent.