The first of the 2015 Nobel Prizes has been announced. Sweden’s Nobel Prize committee says the Nobel Prize for medicine will go to scientists from Ireland, Japan and China.

William Campbell from Ireland and Satoshi Omura from Japan share the prize for their discovery of the drug avermectin. The Nobel committee praised their work on what it calls a “novel therapy.” The treatment fights infections caused by roundworm parasites.

The prize for medicine is also going to Chinese researcher Tu Youyou. She discovered artemisinin. Artemisinin is a drug that has sharply lowered the number of people who die from malaria.

The committee said the discoveries have given the world powerful news ways to fight two powerful diseases. It said those diseases affect hundreds of millions of people every year. The committee added that, “The consequences in terms of improved human health and reduced suffering are immeasurable.”

Ms. Tu is the chief professor at the China Academy of Traditional Medicine. She is also the first Chinese citizen to be awarded the Nobel Prize in medicine.