[14][15] Karikó's work includes scientific research on RNA-mediated immune activation, resulting in the co-discovery with Drew Weissman of the nucleoside modifications that suppress the immunogenicity of RNA.

[24][25] Katalin Karikó was born in Szolnok,[26] and grew up in Kisújszállás, Hungary, in a small home without running water, a refrigerator, or television.

Karikó participated in a clinical trial in which patients with AIDS, hematologic diseases, and chronic fatigue syndrome were treated with double-stranded RNA (dsRNA).

[38] In 1988, Karikó accepted a job at Johns Hopkins University without first informing her lab advisor Suhadolnik of her intention to leave Temple, as recounted in Gregory Zuckerman's 2021 book A Shot to Save the World.

[27] In 1990, while an adjunct professor at the Perelman School of Medicine at the University of Pennsylvania, Karikó submitted her first grant application in which she proposed establishing mRNA-based gene therapy.

Though supported by Elliot Barnathan (who left UPenn in 1997) and David Langer (who then hired her), Karikó found it difficult to gain funding.

[3] A key insight came about when Karikó focused on why transfer RNA (tRNA), used as a control in an experiment, did not provoke the same immune reaction as mRNA.

Karikó and Weissman determined how specific nucleoside modifications in mRNA led to a reduced immune response:[45][3] by replacing uridine with pseudouridine.

[48] Their key finding of a chemical modification of mRNA to render it non-immunogenic was rejected by the journals Nature and Science, but eventually accepted by the publication Immunity.

The mRNA is injected into tiny fat droplets (lipid nanoparticles) which protect the fragile molecule until it can reach the desired area of the body.

[52] Karikó and Weissman founded a small company, RNARx, and in 2006 and 2013 received patents for the use of several modified nucleosides to reduce the antiviral immune response to mRNA.

Soon afterward, the University of Pennsylvania sold the intellectual property license to Gary Dahl, the head of a lab supply company that eventually became Cellscript.

[53] Weeks later, Flagship Pioneering, the venture capital company backing Moderna, contacted her in an attempt to license the patent, at which point Karikó had to tell them it was no longer available.

Karikó was working on establishing the formulated lipid nanoparticle delivery system that encapsulates mRNA in a dense particle through a mixing process.

[55][56] In early 2013, Karikó heard of Moderna's $240 million deal with AstraZeneca to develop a Vascular endothelial growth factor mRNA.

[11] Karikó's research and its specializations have a broad impact with potential implications for areas such as the generation of pluripotent stem cells, and messenger RNA-based gene therapy, as well as "a new class of drugs".

[64][65][66] Katalin Karikó donated the more than half a million dollars she received from her Nobel Prize to her former alma mater, the University of Szeged on 16 April 2024.

[67][68] In 2022, Karikó was awarded The Novo Nordisk Prize along with Drew Weissman for their pioneering forces for more than a decade in discovering a nucleoside-modified form of mRNA.