3 scientists win Nobel Prize in medicine for work on parasite-fighting therapies

Three scientists who discovered breakthrough treatments for some of the worst diseases of the developing world have been awarded the Nobel Prize for physiology and medicine.

William C. Campbell, Satoshi Omura and Tu Youyou were awarded the prize Monday for discoveries that led to the development of antimicrobial treatments for such tropical diseases as river blindness, lymphatic filariasis (also known as elephantiasis) and malaria.

Campbell, 85, an Irish biochemist and parasitologist at Drew University in New Jersey, and Omura, 80, a bioorganic chemist at Kitasato University in Japan and Wesleyan University in Connecticut, will share half the prize for their discovery of the compounds avermectin and ivermectin.

In the 1970s, Omura explored the antibacterial properties of agents produced by the naturally occurring Streptomyces avermectinius micro-organism, which lives in common soil. Campbell acquired Omura’s cultures and conducted extensive tests on farm and domestic animals.

Among the most efficient killers of parasites, he discovered, was a purified version of avermectin. Chemically modified to produce ivermectin, the result kills parasites in their larval stage.

Ivermectin’s global impact on human health is often compared to that of penicillin. It is used around the world to prevent diseases caused by filarial roundworms, including those that cause river blindness and elephantiasis. It is administered to about 300 million people a year.

Its broad use in public health campaigns has “radically lowered” the incidence of both diseases, the Nobel Committee said Monday.

The committee awarded the other half of the prize to Tu, whose work for the Chinese government resulted in the development of artemisinin, a treatment for malaria.

Drawn from the extract of fever-reducing plants long used in traditional Chinese medicines, artemisinin continues to be the primary drug used in the treatment of malaria. Annually, about 400 million doses of the drug are administered.

As head of the Chinese Government’s Project 523 in the 1960s, Tu and her colleagues isolated the active ingredient that protected against the malaria parasite and developed an extraction method.

The Chinese government team’s discovery came at a crucial time in the fight against malaria. By the late 1960s, the agents long used to treat malaria – chloroquine and quinine – were losing effectiveness, and efforts to eradicate the disease faltered.

The Nobel Committee called malaria’s fatality rate “significantly reduced” by artemisinin. In 2013, roughly 198 million people worldwide were infected with malaria and an estimated 598,000 people, most of them in Africa, died of the disease, according to the United Nations World Health Organization.

Tu, 85, has been chief professor of the China Academy of Traditional Chinese Medicine since 2000.

“When it comes to translation of scientific discovery, this is one of the greatest examples of the century,” said Dyann Wirth, chair of the Department of Immunology and Infectious Diseases at the Harvard T.H. Chan School of Public Health and a member of the Alpert Foundation’s scientific advisory prize committee.

“These two discoveries have provided humankind with powerful new means to combat these debilitating diseases that affect hundreds of millions of people annually,” the Nobel Committee said. “The consequences in terms of improved human health and reduced suffering are immeasurable.”