Since April 4, 45 hemorrhagic fever cases have been reported, including 25 deaths, the health ministry said Thursday. Fourteen of those cases are confirmed to be Ebola virus disease, 10 are suspected and 21 are probable.
Now, for the vaccine, it's showtime once again -- and because the vaccine is experimental, meaning it's still being studied, it is administered with strict protocols hinging on informed consent.
The vaccine -- called rVSV-ZEBOV -- must be kept between minus 60 and minus 80 degrees Celsius (minus 76 to minus 112 degrees Fahrenheit) and is believed to last two weeks under basic refrigeration.
"It works by inducing in the body a response that can protect against the Ebola virus. It's usually an antibody response, namely a protein that the body induces to be able to protect against Ebola," Fauci said.
"Right now, there are still vaccine trials that are going on. Originally, the vaccine was shown to have some efficacy when it was used in a ring vaccination in Guinea, but the trials that went on in Sierra Leone and Liberia were merely to prove safety and whether or not it induced an immune response that you might predict would be protective," he said.
Peter Salama, deputy director-general of emergency preparedness and response at the WHO, said Friday that the new vaccinations will begin in Mbandaka next week. They will start with 150 contacts of those infected as well as the contacts of contacts, "so when you add that, it becomes 8,000 to 10,000 people that we look to vaccinate in the first phase." Health care workers will also be vaccinated in the first phase, which will occur over the next three months.
"The estimated efficacy during the trial was 100%, and it's pretty much that simple. It protects you against illness if you're vaccinated before you're infected," Longini said.
Regarding the Ebola vaccine, "as I understand from comments from the World Health Organization and Democratic Republic of Congo this week, it will be used not surprisingly in the same way that it was first studied during the West African Ebola outbreak initially in Guinea," said Lucey, who has treated Ebola patients during outbreaks in Sierra Leone and Liberia.
"This particular vaccine, although it's still experimental, does look hopeful from past experience in Guinea and Sierra Leone, but we don't know for sure," he said. "If in fact it is safe and effective, it really will be a game-changer in terms of being able to more quickly stop future Ebola epidemics."
"It never spreads through the air, thankfully," Lucey said.
"So the idea is to vaccinate people who come into contact or are in contact of people who come into contact with people who have Ebola virus infection," he said. "And importantly, this vaccine can never cause Ebola disease, because it contains only one small part of the Ebola virus, so it could never cause the disease itself."
"Right now, it is impossible to tell what's going to happen with this. Is it going to be a big outbreak? Is it going to be a medium outbreak or a small outbreak? ... We don't know at this point. That's why we're treating it as a very serious situation," Fauci said.
"I think the important takeaway message is that in the outbreak that took place in western Africa, we were able to be able to develop a vaccine and show that it works," he said. "So right now, this is a good example that you can and should be able to do research that tests the efficacy of products during an outbreak, the way it was done in West Africa."
CNN's Meera Senthilingam, Euan McKirdy, David McKenzie and Debra Goldschmidt contributed to this report.