CDC Director Dr. Tom Frieden has just returned from West Africa . He described seeing `` real progress '' in the countries fighting Ebola . But Frieden warned that until there were no more cases , the world was at risk . ` The virus is still very dangerous and we need to be vigilant.
CDC Director Dr. Tom Frieden has just returned from West Africa . He described seeing `` real progress '' in the countries fighting Ebola . But Frieden warned that until there were no more cases , the world was at risk . `` It 's going to be a long , hard fight , '' Frieden said .