Science News

The 2023 Nobel Prize in Physiology or Medicine has been jointly awarded to Katalin Karikó and Drew Weissman “for their discoveries concerning nucleoside base modifications that enabled the development of effective mRNA vaccines against COVID-19.”

Before the pandemic, vaccines were typically based on killed or weakened viruses, individual viral components, or vector-based approaches, all of which required large-scale cell culture and limited the speed of vaccine production. However, Karikó and Weissman’s work focused on using messenger RNA (mRNA) for vaccine development, which was initially challenging due to issues like mRNA instability and inflammatory reactions.

Their breakthrough came when they discovered that in vitro transcribed mRNA was recognized as foreign by dendritic cells, leading to inflammatory responses. They found that the absence of altered bases in in vitro transcribed RNA explained this reaction. To address this, they developed mRNA variants with chemical alterations in their bases, significantly reducing the inflammatory response. These discoveries paved the way for the use of mRNA as a therapeutic and were published in 2005.

Further studies by Karikó and Weissman in 2008 and 2010 showed that base-modified mRNA increased protein production and reduced the activation of enzymes that regulate protein production, removing critical obstacles to mRNA’s clinical applications.

Interest in mRNA technology grew, and after the COVID-19 pandemic outbreak, two base-modified mRNA vaccines for SARS-CoV-2 were developed at record speed and approved in December 2020, demonstrating around 95% protection. This remarkable flexibility and speed of mRNA vaccine development have the potential for use in vaccines against other infectious diseases, therapeutic protein delivery, and cancer treatment.

Their discoveries have been instrumental in the development of over 13 billion COVID-19 vaccine doses globally, saving millions of lives and allowing societies to return to normal conditions during the health crisis. Karikó and Weissman’s work has had a transformative impact during one of the most significant health crises in modern history.

The Nobel Assembly, consisting of 50 professors at Karolinska Institutet, awards the Nobel Prize in Physiology or Medicine. Its Nobel Committee evaluates the nominations. Since 1901 the Nobel Prize has been awarded to scientists who have made the most important discoveries for the benefit of humankind.

Nobel Prize® is the registered trademark of the Nobel Foundation.

Illustration: © The Nobel Prize award ceremonies and banquets. NobelPrize.org.

Source: Press release. NobelPrize.org. Nobel Prize Outreach AB 2023. Tue. 3 Oct 2023. https://www.nobelprize.org/prizes/medicine/2023/press-release/