The Nobel Assembly at the Karolinska Institute in Stockholm announced the award on Monday. (Photo: https://www.nobelprize.org/)
Three scientists, Mary Brunkow, Fred Ramsdell, and Shimon Sakaguchi, have won the 2025 Nobel Prize in Physiology or Medicine for their important research on peripheral immune tolerance.
The Nobel Assembly at the Karolinska Institute in Stockholm announced the award on Monday. Their research explains how the body stops the immune system from attacking its own healthy cells.
According to the Nobel Committee, “their discoveries have laid the foundation for a new field of research and spurred the development of new treatments, for example, for cancer and autoimmune diseases.”
Peripheral immune tolerance is a natural process in the body that helps the immune system fight harmful germs — like viruses and bacteria — without harming healthy tissues.
When this system does not work properly, the immune system may attack the body’s own organs, causing autoimmune diseases such as type 1 diabetes, rheumatoid arthritis, or multiple sclerosis.
The findings of Brunkow, Ramsdell, and Sakaguchi have helped doctors and scientists understand this process better. Their work has also led to new ideas for treating autoimmune disorders and even some forms of cancer, where controlling the immune system is very important.
The Nobel Prize in Medicine is one of the most respected awards in science. Since 1901, it has been given 115 times to 229 laureates for their major contributions to medical research.
Last year, American scientists Victor Ambros and Gary Ruvkun won the prize for discovering microRNA, small molecules that help control how genes work inside cells.
The 2025 winners continue this tradition by advancing our understanding of how the human body protects itself.
The Medicine Prize is the first Nobel announcement of 2025. It will be followed by Physics on Tuesday, Chemistry on Wednesday, and Literature on Thursday. The Nobel Peace Prize will be announced on Friday, and the Economics Prize will follow on October 13.
Each Nobel Prize includes a cash award of about $1.2 million, along with a gold medal and diploma. The official ceremony will take place on December 10, the death anniversary of Alfred Nobel, the Swedish scientist and inventor who created the prize.
