Our data demonstrate that early inflammation can be beneficial for maximising the development of vaccine-induced CD4+ T cell immunity; mechanistically, CD11b+Ly6GnegLy6Chi IMs play an important role in providing spatial and functional cues that position CD4+ T cells to the foci of infection, from where CD4+ T cells can be sustained by having access to IL-12 and antigen stimulation. The gene discussed is ITGAM; the disease is infection.