On this day, January 23, 1922, fourteen year old Canadian Leonard Thompson received the first successful insulin injection as a treatment for diabetes. Thompson, who was in a coma due to Type 1 Diabetes, was given an injection on January 11, but apparent impurities caused a sever allergic reaction. Biochemist James Collip worked to improve and purify the ox-pancreas extract. The second injection on January 23 brought the boy out of his coma and was a complete success. Prior to the development of insulin, people with Type 1 diabetes did not survive for more than a few weeks or months with the disease.