A woman receives the rVSV-ZEBOV Ebola vaccine at a clinical trial in Conakry, Guinea. The vaccine appears effective after only one shot. Cellou Binani/AFP/Getty Images hide caption

itoggle caption Cellou Binani/AFP/Getty Images

Using a digital device that displays Braille characters, Haben Girma talks with President Obama at a White House ceremony marking the 25th anniversary of the Americans with Disabilities Act. White House photo/Courtesy of Haben Girma hide caption

itoggle caption White House photo/Courtesy of Haben Girma

In this image taken from a November 2012 video, Cecil the lion is shown in Hwange National Park in Zimbabwe. Paula French via AP hide caption

itoggle caption Paula French via AP

Mineral supplements, ape-style: A female chimp called Kana eats clay in the Budongo Forest of Uganda. A.Schel/Budongo Conservation Field Station/Animal Ecology, Utrecht University, The Netherlands hide caption

itoggle caption A.Schel/Budongo Conservation Field Station/Animal Ecology, Utrecht University, The Netherlands

The bar chart tells all: That's how eighth-graders at Bakgatle Community Junior Secondary School in Botswana can compare the HIV infection rate of older men and of teenage boys. Don Boroughs for NPR hide caption

itoggle caption Don Boroughs for NPR

Cecil the lion is shown walking in Zimbabwe's Hwange National Park in a YouTube video from July 9, 2015. Credit: Bryan Orford Bryan Orford/YouTube hide caption

itoggle caption Bryan Orford/YouTube