Immunization is an important tool to fight diseases caused by viral, bacterial or fungal pathogenes. The invention provides a new approach for the generation of oligomeric vaccines. The underlying principle is the high affinity interaction between S-protein and a modified S-tag of bovine pancreatic RNase A which is applied to hemagglutinin (H5). The technology can be applied to produce high molecular vaccines. They have many advantages compared to recently used vaccines including high immunogenicity, high stability, short production time and lower production costs. The approach could therefore be used for the immunization of livestock.