https://www.nejm.org/doi/full/10.1056/NEJMp2034334

On the Shoulders of Giants — From Jenner’s Cowpox to mRNA Covid Vaccines

In September 2008, Katalin Karikó, Drew Weissman, and their colleagues at the University of Pennsylvania modified messenger RNA (mRNA) using nucleoside analogues. These modifications stabilized the molecule and eliminated its capacity for inducing innate immunity, thereby making mRNA a promising tool for both gene replacement and vaccination.¹ In December 2020, on the basis of safety and efficacy data generated in two large, placebo-controlled studies, the Food and Drug Administration (FDA) issued emergency use authorizations for two mRNA vaccines for the prevention of Covid-19. Clearance of this hurdle by the first mRNA vaccines represents the most recent in a series of breakthroughs in the realm of viral vaccines, each building on the last and each with a compelling record of disease prevention.