This invention relates to compositions (e.g. vaccine compositions) which can be used to provide a subject with protective immunity against a parasite infection. The compositions comprise: (i) an immunologically effective amount of a nucleic acid (e.g. a nucleic acid-based vaccine) comprising a sequence which encodes a parasite macrophage migration inhibitory factor (MIF) antigen； (ii) a parasite MIF antigen； or (iii) an antibody which specifically binds to a parasite MIF antigen. The compositions may be used to treat infections and diseases caused by parasitic protozoans, such as a Plasmodium parasite, or parasitic helminths.
