The T Cell-Directed Vaccine BNT162b4 Encoding Conserved Non-Spike Antigens Protects Animals from Severe SARS-CoV-2 Infection

To enhance T cell immunity across epitopes infrequently altered in SARS-CoV-2 variants, the authors designed BNT162b4, an mRNA vaccine component which was intended to be combined with BNT162b2, the spike-protein-encoding vaccine.