The blood of Ebola virus survivors can be used to treat people infected in West Africa's outbreak, the World Health Organization has decided following a two-day meeting with researchers.

WHO assistant director general Marie Paule Kieny held a news conference on Friday to discuss results from the meeting of more than 150 participants who aimed to speed up development of experimental drugs and vaccines. The meeting wrapped up Friday in Geneva.

"We have agreed that whole blood therapies and convalescent serums may be used to treat #Ebola," the UN health agency tweeted, citing Marie-Paule Kieny, WHO's assistant director general.

"Blood from #Ebola survivors [people who recovered] might help those who are still infected and still sick to fight the virus," she added.

Two "promising" Ebola vaccines have also been identified. Safety results from clinical trials may be available this November, she said.

The two vaccines include a chimpanzee adenovirus made by GlaxoSmithKline (GSK) and a livestock virus called vesicular stomatitis virus (VSV-EBOV), WHO said.

Kieny said the first vaccine likely to be used in the outbreak would be the VSV-EBOV one developed at Canada's National Microbiology Laboratory in Winnipeg.

On Thursday, the vaccine was approved by the U.S. Food and Drug Administration (FDA) to start its own clinical trial.

The Canadian government licensed VSV-EBOV to a U.S. company, NewLink Genetics.

The experimental Ebola vaccines could be ready for use before the end of 2014, if data from the first human safety trials are promising.

The total number of cases in the outbreak in Guinea, Sierra Leone and Liberia stands at 3,685, with 1,841 deaths, WHO said Friday. WHO has called it the largest, most severe and most complex outbreak of Ebola disease in history.

So far, three people have been immunized out of 20 healthy adults who will be injected with the GSK vaccine.

Elsewhere, UN Secretary General Ban Ki-moon told reporters that the UN is establishing an "Ebola crisis centre."

"The number of cases is rising exponentially. The disease is spreading far faster than the response. People are increasingly frustrated that it is not being controlled," Ban told reporters.

"The goal is to stop Ebola transmission in affected countries within six to nine months, and to prevent the
international spread of the virus," he said. "This can be done only if the urgent and necessary mobilization is done both in the affected countries and by the international community."

Dr. Anthony Fauci

Dr. Anthony Fauci, director of the U.S. National Institute for Allergy and Infectious Diseases, says there's a misperception that experimental interventions will control the Ebola outbreak in West Africa. (Alex Brandon/Associated Press)

The Canadian government has said it will donate between 800 and 1,000 doses of an experimental Ebola vaccine to the WHO for use in the Ebola response.

U.S. missionary enters treatment

On Friday, a U.S. missionary infected with the Ebola virus in Liberia entered a treatment centre in Nebraska.

Dr. Rick Sacra, a 51-year-old Boston physician, worked for SIM USA in West Africa, as did U.S. missionary Nancy Writebol.

Doctors overseeing Sacra’s treatment said he is sick but in stable condition.

Writebol received ZMapp, an experimental drug cocktail. Earlier this week, she credited her recovery to ZMapp, supportive care, medical treatment in Liberia and in Atlanta and her faith.

Other interventions urged

Dr. Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases and other doctors caution that what’s most likely to control the outbreak are proven interventions, such as health-care workers in the field, more protective gear, basic medical care and better tracking of the sick.

"I think there is a bit of a misperception that the epidemic is out of control and what is going to control it is these experimental interventions," Fauci said on Thursday.

If the early human safety trials work, experts say funding and scaling up production of the experimental therapies will also be a challenge.

"Although the development of medicines against Ebola is ongoing, the majority of patients affected by the virus do not have access to these treatments," Health Canada said in a statement on Friday.

"Regulators therefore also stress that the search for pharmaceutical interventions must not detract from the need to strengthen basic health-care measures such as fluids and electrolytes management and to carefully observe the impact and contribution of these measures in the overall response to the disease."

With files from The Associated Press, The Canadian Press, Reuters and CBC's Kas Roussy