Zika virus has been known since 1947, but it was only with its spread to the Americas that it was declared a public health emergency of international concern by the World Health Organization (WHO)1. As Zika virus spread throughout South and Latin America, cases of babies born with microcephaly, where the head is smaller than normal, dramatically increased. Cases of Guillain-Barré syndrome increased as well2.
The 2014 – 2016 Ebola outbreak was the largest in history. It began with a few cases in Guinea, but quickly spread to Liberia and Sierra Leone, with some limited cases occurring in other countries. The outbreak grew so serious that the World Health Organization (WHO) declared it a public health emergency of international concern1. However, even with international assistance, the disease was hard to combat. Preventing the spread of Ebola virus disease was difficult due to the lack of vaccines and the ease of transmission of the virus2. Treating it was no easier. At the start of the outbreak, there were no approved treatments for Ebola virus disease3. As the crisis continued, some treatments were developed, but they still needed to be tested for safety and efficacy.