evidence: During the SARS-CoV-2 pandemic, mRNA-based vaccines were shown to be highly effective against SARS-CoV-2 and were developed and administered at unprecedented speed to millions of people globally to combat COVID-19 (Box 1). These vaccines, initially developed by Pfizer–BioNTech and Moderna, have validated the platform and stimulated substantial interest in the application of mRNA for both prophylactic and therapeutic indications. [...] Decades of progress in mRNA design and nucleic acid delivery technology, together with the discovery of novel antigen targets have made mRNA vaccines an extraordinary tool for combating emerging pandemics and existing infectious diseases. The first two mRNA vaccines, which were developed at revolutionary speed to fight SARS-CoV-2, have exceeded expectations and offer hope that the COVID-19 pandemic will end. Furthermore, these vaccines have elevated LNPs and RNA therapy from small-market products for niche diseases to a prophylactic treatment deployed successfully in large swathes of the population. The resultant abundance of positive safety and efficacy data, together with a proven path to regulatory approval, leave us optimistic that mRNA therapeutics will transform modern medicine’s approach to vaccination1,5, cancer immunotherapy247,248,249, protein replacement therapy15,23 and beyond250. [...] Shimabukuro, T. T., Cole, M. & Su, J. R. Reports of anaphylaxis after receipt of mRNA COVID-19 vaccines in the US — December 14, 2020-January 18, 2021. JAMA325, 1101–1102 (2021).