A description is given of vaccine compositions that combine, in equal proportions, the extracellular domains of Her1 and Her2 growth factor receptors or fragments thereof and, in addition, proteoliposomes of very small size deriving from outer membrane proteins of Neisseria meningitidis and GM3 ganglioside (GM3/VSSP), which are intended for subcutaneous administration. The compositions described allow antibodies to be induced for treating malignant tumours and offer advantages owing to the fact that they successfully eliminate the entire mass of the tumour and prevent return of the tumour from the appearance of resistant variants.