Using a computational design methodology, SARS-CoV-2 spike proteins containing engineered amino acid changes to the receptor binding domain (RBD) were designed. These engineered spike proteins improved the immune response upon immunization of animals. An engineered RBD was also expressed at greater yield, had increased temperature stability, and improved the immune response upon immunization of animals. Specifically, the disclosed RBD designs can be produced approximately 7 times more efficiently than the native sequence, facilitating vaccine manufacturing on a global scale.