Therefore, the low-dose (10 μg) regimen of the next-generation COVID-19 vaccine, mRNA-1283, induces polyfunctional and durable CD4+ and CD8+ T cell immunity comparable to the standard 100 μg mRNA-1273 vaccine, supporting a dose-sparing strategy without compromising long-term cellular protection against severe COVID-19. The gene discussed is CD8A; the disease is COVID-19.