♦ The 2025 Nobel Prize in Physiology or Medicine was awarded to Mary E. Brunkow, Fred Ramsdell, and Shimon Sakaguchi for their work on how immune systems work in determining what should be attacked or protected.

♦ The prize was announced at the Nobel Assembly at Karolinska Institutet in Stockholm, Sweden, on 6 October 6, 2025.

♦ Among this Medicine winners, Brunkow and Ramsdell are from the USA, while Sakaguchi is from Japan.

♦ The research by the two Americans proved to be the second chapter of something Sakaguchi had worked on separately some years ago.

♦ After Brunkow and Ramsdell’s findings, Sakaguchi and other scientists managed to stitch their work together.

♦ What have the three winners done?

♦ The human body has a powerful and complex immune system, which not just fights off various bacteria and viruses, but also knows what cells should not be attacked.

♦ According to the Nobel Prize’s official press release, “Mary Brunkow, Fred Ramsdell and Shimon Sakaguchi are awarded the Nobel Prize in Physiology or Medicine 2025 for their fundamental discoveries relating to peripheral immune tolerance.

♦ The laureates identified the immune system’s security guards, regulatory T cells, which prevent immune cells from attacking our own body.”

♦ Where do the three scientists work?

♦ Mary Brunkow, born in 1961, works at the Institute for Systems Biology, Seattle, USA.

♦ Frederick Ramsdell, born in 1960, works at Sonoma Biotherapeutics, San Francisco, USA.

♦ Shimon Sakaguchi, born in 1951, works at Osaka University, Japan.

♦ Nobel Prizes generally follow the same schedule every year, with the Medicine prize coming first, followed by Physics, Chemistry, Literature, Peace, and Economics.