MONROVIA, LIBERIA - AUGUST 13:  Liberian Foreign Affairs Minister Augustine Ngafuan hand-carries boxes an experimental Ebola-fighting drug ZMapp on a Delta Airlines flight from New York's JFK airport to Monrovia on August 13, 2014 in Monrovia, Liberia. The Liberian government says the drug is meant to be used to treat Liberian doctors infected by the deadly virus which has killed more than 1,000 people in four West African countries.  (Photo by John Moore/Getty Images)