Disclosed is a vaccine composition comprising as active principle the conjugated protein hrEGF-rP64K, wherein each P64K protein molecule is bound to two hrEGF molecules and the conjugation ratio between rP64K carrier protein and the hrEGF is 12.04:24.05 and said composition is an homogenous composition of the conjugated hrEGF-rP64K being free of others molecular species including hrEGF polymers or free hrEGF.