A composition comprising iron (ferric or ferrous ions) and at least one vaccine adjuvant. The vaccine adjuvant may be LPS (lipopolysaccharide), monophosphoryl lipid A, a toll-like receptor agonists, Poly IC, a pattern recognition receptor (PRR) ligand, a NOD-like (nucleotide oligomerization domain) receptor ligand, a lectin receptor, alum, MF95, saponin, Quil-A or QS21. The iron may be iron chloride, iron oxides, iron phosphate or iron hydroxide. The composition may be suitable for use in human or veterinary medicine. The composition can be used in combination with an antigen as part of a vaccine or immunomodulatory product. Also claimed is a composition comprising monophosphoryl lipid A and iron (II) chloride (FeCl2). The composition may be used in the preparation of a vaccine or immunomodulatory product. The ambient endotoxin levels in particular matter (PM) from various environments (traffic, green and industrial) was monitored and the ability of host cell immune recognition of LPS was assessed for each sample. Analysis of metals in the environmental samples was carried out. Higher levels of iron was present in traffic samples, where there was highest levels of TLR4 stimulation by LPS.
