Up to 1000 doses of an experimental Ebola vaccine are headed for west Africa as the world scrambles to halt the spread of the virus which felled dozens more victims this week.
Canada said it would send doses of a vaccine called VSV-EBOV which has shown promise in animal research, but never been tested in humans.
Watch: Videographic on Ebola
Hard-hit nations were also anxiously awaiting a barely-tested drug from the US called ZMapp which is expected to arrive this week as they hope to save hundreds infected by the tropical disease.
The death toll in the worst-ever epidemic of Ebola since its discovery four decades ago had climbed to 1069, according to the World Health Organisation which said 56 had died in two days.
Nearly 2000 people have now been infected.
The disease has hit doctors hard in the ill-equipped and fragile health systems of the worst-hit west African nations, Guinea, Liberia and Sierra Leone.
Liberia is scrambling to save two infected doctors and is hoping that the ZMapp serum, which has shown positive early results, arrives in time. The government said on Tuesday it had received approval from the US Food and Drug Administration for the use of the drug.
Sierra Leone's health ministry spokesman Sidi Yahya Tunis told AFP the country had officially requested a shipment of the serum as the nation lost its second top doctor to the virus.
The death of Modupeh Cole, a senior physician in the Sierra Leonean capital Freetown, came just a fortnight after the country's only virologist and leading Ebola expert, Umar Khan, died of the tropical disease.
There is currently no available cure or vaccine for Ebola, which the WHO has declared a global public health emergency, and the use of experimental drugs has stoked a fierce debate.
The WHO declared this week it was ethical to try largely untested treatments "in the special circumstances of this Ebola outbreak".
Nigeria has also had an outbreak of Ebola, and three people have died from the virus in the megacity of Lagos.
A nurse based in the city who was exposed to the virus travelled to the eastern part of the country, breaking a quarantine order, government said.
Canada's Health Minister Rona Ambrose said between 800 and 1000 doses of the VSV-EBOV vaccine would be distributed through the WHO.
Meanwhile the company behind the ZMapp drug said it had sent all its available supplies to the region following an outcry over the fact it had so far only been used on Westerners, but supplies are extremely limited.
Its effectiveness is also far from proven, having only previously been tested on monkeys. It appears to have had a positive effect on two US aid workers infected in Liberia, but an elderly Spanish priest also infected in the country, died in a Madrid hospital on Tuesday despite being treated with ZMapp.
As west African countries waited for help from afar, the international community took further measures to prevent the spread of the virus.
Germany called on its nationals to leave Guinea, Liberia and Sierra Leone, although it said it was keeping its embassies open. In Riyadh, representatives of the Gulf monarchies met to discuss ways to guard against the epidemic ahead of the the arrival of millions of Muslims from around the world for the the annual pilgrimage to Mecca in early October.
'We are all scared'
In Freetown, the tropical fever was the only topic of conversation. "We are all scared because of the way Ebola is spreading but we are taking all the necessary precautions," said Waisu Gassama, 27, who works in the HIV department of the dilapidated, century-old Connaught Hospital.
Outside the hospital, soldiers said they had been drafted in to guard doctors and nurses, many of whom had been targeted by angry mobs blaming modern medicine for exacerbating the epidemic.
Terror has gripped the impoverished west African countries, with harrowing tales emerging of people being shunned by their villages as the virus fells those around them.
When AFP visited the Liberian village of Ballajah, some 150 kilometres from the capital Monrovia, 12-year-old Fatu Sherrif had been locked away with her mother's body without food and water for a week. Her cries went unanswered as panicked residents fled the village when both her parents fell sick.
Fatu later died and her brother Barnie, 15, despite testing negative for Ebola, was left alone and hungry in an abandoned house.
"Nobody wants to come near me and they know - people told them that I don't have Ebola," he said.