The present invention relates to antigenic heterocomplexes of TNF-alpha and acarrier protein for obtaining a humoral immune response in a mammal withproduction of antibodies that neutralize the biological activity of TNF-alphaas well as to a method for preparing the same. The antigenic protein TNF-alphaand the carrier protein are conjugated in presence of EDTA usingglutaraldehyde , formaldehyde and glycine and, in some embodiments, DMSO,allowing thus to improve immunogenicity and stability. The following proteinscan be used as carrier: keyhole limpet Haemocyanin (KHL) , bovine serumalbumins (BSA) , inactivated bacterial toxins such as tetanus or diphteriatoxins (TT and DT) , the purified protein derivative of tuberculin (PPD) andProtein D from Haemophilus Influenzae .
