Tu Youyou: one artemisia plant that saved millions worldwide

In 1969, at thirty-nine, Tu Youyou was handed an assignment: join a project with the code number 523 and take charge of its traditional-medicine group against malaria.

Malaria was everywhere that year. The old drugs, chloroquine among them, were losing ground to resistance. Hundreds of millions of people were infected annually and hundreds of thousands died, most of them children in Africa. The difficulty of the task showed in who was given it. Tu had trained as a pharmacognosist in the pharmacy department of Beijing Medical College. No doctorate, no years abroad, no academy title. People later called her the three-nothing scientist.

What she had was a weapon almost nobody else had bothered to open: several thousand years of Chinese medical texts.

She and her team went through the old books and the folk remedies, gathering more than two thousand prescriptions into a compilation of over six hundred pages. From those they selected six hundred and forty and tested them one by one as extracts. Again and again the parasite grew in the mice as though nothing had been done. Batch after batch came back useless.

The turn came from a book written more than sixteen hundred years earlier. In Ge Hong's emergency prescriptions from the Eastern Jin dynasty there is a line: "A handful of qinghao, steeped in two sheng of water, the juice wrung out and drunk to the last drop."

Why had the ancients wrung out the juice instead of boiling the plant the usual way? Tu stared at that sentence until a possibility opened: heat might be exactly what destroyed the active compound.

She switched to ether, which boils at a far lower temperature. On 4 October 1971, sample number 191 — a neutral ether extract of qinghao — inhibited the parasite completely. One hundred percent.

One hundred and ninety failures came before it.

The next step was harder. Animal tests had shown a possible toxic reaction. Could it go into people? There was no time in those years for a full safety program. Tu submitted a report volunteering to take the drug herself, and she and two colleagues checked into a hospital and became the first people to test it in a human body. With their own bodies they pressed the confirm key for malaria patients everywhere.

In 1972 the artemisinin crystal was isolated. The combination therapies built on it became the global standard for malaria, and the lives it has saved are counted in millions.

The cost was real. Years of working with ether and other solvents damaged her liver, and she developed toxic hepatitis. Her children were sent to a full-time nursery, and when her daughter saw her again the child did not recognize her mother. Years later she spoke of it in a level voice. "The country needed it then. Our generation felt that what the country needed was what had to be done."

One hundred and ninety-one experiments could not save the people who were dying then. The hundred and ninety-second could. A scientist's love looks like this: fix on the target, and count the failures out one at a time until they are finished.

In 2015, at eighty-five, Tu Youyou stood on the stage for the Nobel Prize in Physiology or Medicine. She was the first scientist trained and working in mainland China to win a Nobel in the sciences. The title of her lecture was so gentle it hardly sounded like an acceptance speech: "Artemisinin — A Gift from Traditional Chinese Medicine to the World."

She did not retire afterward. Her team kept working on the problem of resistance to artemisinin. Someone asked her what she thought of the label three-nothing scientist, and her answer was flat. "This is my trade. A researcher finishes the work that needs finishing. That is enough."

Between one line of classical Chinese written in the Eastern Jin and a lifesaving drug in the world's medicine cabinets today lie sixteen hundred years — and the back of one old woman, sitting in a laboratory for decades.