Katalin Karikó shared the 2023 Nobel Prize in Physiology or Medicine for discoveries enabling effective mRNA vaccines.
Karikó and Drew Weissman found that modifying messenger RNA’s nucleosides could prevent an excessive inflammatory reaction when synthetic mRNA entered cells. That breakthrough helped make mRNA practical as a medical technology.
Their research became especially important during the COVID-19 pandemic. Vaccines made by Pfizer–BioNTech and Moderna use mRNA instructions that teach cells to produce a viral spike-protein fragment, prompting an immune response.
The Nobel citation recognized their discoveries concerning nucleoside base modifications. Karikó did not single-handedly invent every mRNA vaccine; her work formed part of a much longer development involving many researchers, institutions and clinical teams.