By ensuring vaccines are invented and distributed, Bill Gates says, his foundation is dramatically reducing the number of childhood deaths in poor countries. Marie McGrory/NPR hide caption

itoggle caption Marie McGrory/NPR

A pregnant Somali woman gets a tetanus shot at a clinic in Mogadishu in 2013. The vaccination initiative was launched by the GAVI Alliance, UNICEF and the World Health Organization. Carl de Souza/AFP/Getty Images hide caption

itoggle caption Carl de Souza/AFP/Getty Images

Yonta, 6, rests with her brother Leakhena, 4 months, under a mosquito bed net in the Pailin province of Cambodia, where deaths from malaria have decreased sharply in the past two decades. Paula Bronstein/Getty Images hide caption

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Children get tested for malaria at a clinic near the Myanmar border in Sai Yoke, Thailand. Drug-resistant strains of the parasite have appeared in the region over the past few years. Surkree Sukplang/Reuters /Landov hide caption

itoggle caption Surkree Sukplang/Reuters /Landov

A health worker administers the malaria vaccine at a clinical trial in Kilifi, Kenya. Joseph Okanga/Reuters /Landov hide caption

itoggle caption Joseph Okanga/Reuters /Landov

A Cambodian boy gets tested for malaria at a clinic along the Thai-Cambodian border in 2010. Three strains of drug-resistant malaria have emerged from this region over the past 50 years. Paula Bronstein/Getty Images hide caption

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A red blood cell infected with malaria parasites (blue) sits next to normal cells (red). NIAID/Flickr.com hide caption

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More than a hundred different species of Anopheles mosquitoes can transmit malaria to people. Adam Cole/NPR hide caption

itoggle caption Adam Cole/NPR

An extract of sweet wormwood has been used in China for thousands of years to treat malaria, but being able to make mass quantities of the extract has been elusive, until now. Sarah Cuttle/Getty Images hide caption

itoggle caption Sarah Cuttle/Getty Images

Chiara Andolina, a malaria researcher in Thailand, feeds her mosquito colony by letting the insects bite her right arm. These mosquitoes are picky and will dine only on live human blood. Ben de la Cruz/NPR hide caption

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Mosquitoes like this one can carry the virus that causes dengue fever, which may become a bigger problem in some regions as biodiversity is lost. James Gathany/CDC Public Health Image Library hide caption

itoggle caption James Gathany/CDC Public Health Image Library

Shaken with splash of malaria drug, please. The original James Bond martini is made with gin, vodka and Kina Lillet, a French aperitif wine flavored with a smidge of the anti-malaria drug quinine. Karen Castillo Farfan/NPR hide caption

itoggle caption Karen Castillo Farfan/NPR

The U.S. Army distributed a monthly pinup calendar to GIs, which encouraged them to protect themselves from malaria-carrying mosquitoes. Cartoon by Frank Mack for the U.S. Army./Courtesy of the Images from the History of Medicine. hide caption

itoggle caption Cartoon by Frank Mack for the U.S. Army./Courtesy of the Images from the History of Medicine.

In rural areas of Myanmar, villagers can buy inexpensive packets of drugs, called Ya Chut, when they have malaria. But these local remedies often don't contain adequate amounts of malaria medicines. Ben de la Cruz/NPR hide caption

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