West Africa

An ambulance in Sierra Leone is sent out to pick up a suspected patient. But after two wrong turns and several stops for directions, it arrives at the home of a 14-year-old boy with no signs of Ebola.

Congregants at Trinity Episcopal Church come from many countries, including in West Africa. No one had visited the virus-stricken nations, yet fearful worshippers began skipping services.

Anthony Banbury is stepping down as the head of the U.N.'s Ebola mission. He says the Ebola can't become entrenched in West Africa. And he thinks the fight is heading in the right direction.

Big questions have bedeviled virus hunters for 38 years: Why do people differ in their response to Ebola? Is it becoming more or less dangerous? There's now more evidence about who gets sick and why.

"We run the risk of going from hysteria to a sense of indifference," says the now-recovered physician. "And I think that is even more dangerous than our fear."

Can you run a clinical trial without a placebo group? That's one of the questions facing researchers in West Africa.