Among those marching down the Champs-Elysées today for Bastille Day are a special kind of military personnel: army medics, doctors, nurses, and laboratory technicians. These men and women are taking an active role in the fight against the Ebola virus in western Africa. After one week of intense training, a group of volunteers is about to begin a mission in Guinea. José Blanc-Lapierre and Tatiana Daligault report.