You might not know the name Karl Landsteiner, but his discoveries have saved the lives of so many millions of us.

In 1901, Landsteiner discovered the existence of blood types A, B, AB and O, and that people of the same or compatible types can receive transfusions from one another. The first successful blood transfusion occurred in 1907 as a direct result of his work, which led to advances in medicine, therapies, and surgery.

Landsteiner is also credited with laying the groundwork, together with fellow scientist Erwin Popper, that led to the discovery of the polio virus. This was the first step towards developing a treatment for the disease which affected millions of children worldwide.

On what would be his 148th birthday, we thank you, Karl Landsteiner, for helping us lead longer, healthier lives.