Measles, the reorganization of the World Health Organization and the Zika virus could all make global health headlines in 2016. Rich Pedroncelli, Raphael Satter, Felipe Dana/AP hide caption

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Medical workers surround 34-day-old Noubia, the last known patient to contract Ebola in Guinea, as she was released from a Doctors Without Borders treatment center in Conakry on Nov. 28. Cellou Binani /AFP/Getty Images hide caption

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Adama Sankoh, 40 (center), who contracted Ebola after her son died from the disease late last month, stands with health officials the moment after she was discharge from Mateneh Ebola treatment center outskirt of Freetown, Sierra Leone. Alie Turay/AP hide caption

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Transgender performers walk backstage during an event to mark World AIDS Day in 2013. A new WHO report demonstrates extremely rates of HIV infection among transgender women in 15 countries. Prakash Mathema/AFP/Getty Images hide caption

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Since the first case on May 20, confirmed cases of Middle East respiratory syndrome, or MERS, have swelled to at least 30 in South Korea. Chung Sung-Jun/Getty Images hide caption

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The Ebola outbreak "overwhelmed" the World Health Organization and made it clear the agency must change, WHO's director-general, Dr. Margaret Chan, said Monday in Geneva. Fabrice Coffrini /AFP/Getty Images hide caption

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Dr. Margaret Chan, director-general of the World Health Organization, has said of Ebola: "It overwhelmed the capacity of WHO, and it is a crisis that cannot be solved by a single agency or single country." Fabrice Coffrini/AFP/Getty Images hide caption

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Ebola was out of control in Liberia in August, when this picture was taken. Dominique Faget/AFP/Getty Images hide caption

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Health workers rest outside a quarantine zone at a Red Cross facility in the town of Koidu, Kono district in Eastern Sierra Leone on Friday. The World Health Organization says the number of Ebola deaths in the current outbreak has exceeded 7,000. Baz Ratner/Reuters/Landov hide caption

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Community workers build an Ebola clinic on Nov. 8 in Lokomasama, near Port Loko, Sierra Leone. The community decided to organize and fight the disease — building a holding center for suspected cases, enforcing a travel ban. It created a $100 fine for a handshake and a $200 fine plus six months in jail for an illegal burial. Francisco Leong/AFP/Getty Images hide caption

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Among the dilemmas that arise when health workers are in their protective garb: What if you can't find the person assigned to be your Ebola Treatment Unit partner? John W. Poole/NPR hide caption

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When a high-risk patient is evacuated, strict precautions are followed. Above, aid workers and doctors in protective gear transfer Manuel Garcia Viejo, a Spanish priest diagnosed with Ebola, to a waiting ambulance at a Madrid airport. Spanish Defense Ministry/AP hide caption

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A licensed clinician is decontaminated before disrobing at the end of a simulated training session by CDC in Anniston, Ala. Training can take a several weeks, making some employers reluctant to encourage their medical workers to volunteer in the Ebola outbreak. Brynn Anderson/AP hide caption

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Adrian Hill, director of the Jenner Institute and chief investigator of the trials with an Ebola vaccine his organization developed, holds a vial of the vaccine. Steve Parsons/WPA Pool/Getty Images hide caption

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A World Health Organization worker trains nurses how to use Ebola protective gear in Freetown, Sierra Leone. Michael Duff/AP hide caption

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Workers wait to spray disinfectant on medical staff after they treat Ebola patients at a clinic run by Doctors Without Borders, in Monrovia, Liberia. Tommy Trenchard for NPR hide caption

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Protective equipment is in short supply. Here, a Liberian burial team carefully disinfects its gloves before disposing of them. John Moore/Getty Images hide caption

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A health worker cleans his hands with chlorinated water before entering an Ebola screening tent at the Kenema Government Hospital in Sierra Leone. More than 300 Sierra Leoneans have died of the disease. Michael Duff/AP hide caption

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