Summary
We are developing vaccine antigens for SARS-CoV-2 that focus the antibody response onto neutralizing epitopes in the receptor binding domain (RBD) of the viral Spike (S) protein. Booster antigens derived from variants of SARS-CoV-2 would especially benefit from being limited to the RBD, due to the preponderance of conserved but non-neutralizing epitopes in the full-length S protein. However, RBD-only vaccines face the technical limitations of aggregation and poor expression, due to hydrophobic patches on the RBD that form the inter-subunit interfaces in the native S protein. We have overcome
