Genes for proteins which spontaneously form dimers and/or oligomers can be recombinantly linked together, which upon expression in E. coli produces stable dimeric fusion proteins that spontaneously self-assemble into enormous, polyvalent complexes having increased immunogenicity and functionality. Linear, network and agglomerate complexes with enormous sizes and polyvalences are constructed using glutathione S-transferase, Norovirus P domains (NoV P− and NoV+), the protruding (P) domain of hepatitis E virus (HEV P), the astrovirus P domain (AstV), a monomeric peptide epitope (M2e of influenza virus), and/or a protein antigen (VP8* of rotavirus) fused in different combinations. The resulting complexes can contain hundreds to thousands NoV P-protein, HEV, AstV, M2e and/or VP8* copies and exhibit higher immunogenicity than the individual proteins alone. The large size and multivalent nature of the complexes are candidates as a bivalent or multivalent vaccines against Norovirus and other pathogens, and for generation of antibodies for diagnosis and research purposes.