The present disclosure provides nanostructures and nanostructure-based vaccines. Some nanostructures of the present disclosure display antigens capable of eliciting immune responses to infectious agents such as bacteria, viruses, and pathogens. Some vaccines of the present disclosure are useful for preventing or decreasing the severity of infection with an infectious agent, including, for example and without limitation, lyme disease, pertussis, herpes virus, orthomyxovirus, paramyxovirus, pneumovirus, filovirus, flavivirus, reovirus, retrovirus, meningococcus, or malaria. The antigens may be attached to the core of the nanostructure either non-covalently or covalently, including as a fusion protein or by other means disclosed herein. Multimeric antigens may optionally be displayed along a symmetry axis of the nanostructure. Also provided are proteins and nucleic acid molecules encoding such proteins, vaccine compositions, and methods of administration.