Abstract: Disclosed is the invention relates to proteins derived from parasitic nematodes which confer protective immunity against infection by parasitic nematodes, to nucleotide sequences encoding these proteins, to recombinant molecules containing such sequences to host cells transformed with such recombinant molecules and methods for the production of the nucleotide sequences recombinant molecules and hosts. The invention also relates to vaccines comprising proteins of the invention together with suitable carriers or diluents and to antibodies raised against proteins of the invention.