Many big pharma companies were able to roll out vaccines against SARS-CoV-2 in record time by retooling their existing experimental mRNA gene therapies to carry a new payload. Whereas these cancer vaccines originally coded a single RNA molecule neoantigen concatemer that could be optimally presented on specific HLA receptors to enhance CD8+ T cell anti-tumor responses, they can now deliver optimized versions of the spike protein receptor binding domain to arouse production of protective neutralizing antibodies.