The WHO and others are waging a battle to stop an "ominous spike" in Ebola cases in eastern Sierra Leone, while the western region is also a concern.
Lessons learned this fall: (1) don't over-reassure, (2) acknowledge uncertainty, (3) don't overemphasize panic, and (4) don't ridicule overreactions.
Ebola incidence in Sierra Leone health workers was 100-fold that of the general population.
As groups tailor their response, the outbreak hits 17,800 cases, 6,331 deaths.
The CDC has fielded Ebola questions about 650 people, with 61 (9%) tested for the disease.
Several early vaccine trials are under way, and another American is airlifted home.
Ebola cases have now reached 17,145, and deaths total 6,070.
Foreign governments and aid groups need to show more flexibility, MSF leader says.
Strong international support is still needed, including treatment units, a top WHO official said.
Study results showed a good immune response at a high dose.
