The present invention provides nanoparticles and compositions of various constructs that combine meta-stable viral proteins (e.g., RSV F protein) and self-assembling molecules (e.g., ferritin, HSPs) such that the pre-fusion conformational state of these key viral proteins is preserved (and locked) along with the protein self-assembling into a polyhedral shape, thereby creating nanoparticles that are effective vaccine agents. The invention also provides nanoparticles comprising a viral fusion protein, or fragment or variant thereof, and a self-assembling molecule, and immunogenic and vaccine compositions including the same.
