Canada will be donating up to 1,000 doses of an experimental Ebola vaccine, following a decision from the World Health Organization that it would be ethical to use untested treatments to try to contain the current outbreak in West Africa.

WHO Assistant Director-General Dr. Marie-Paule Kieny helped make the announcement Tuesday. She said countries that offer experimental drugs or vaccines to consenting patients must also collect data for research purposes.

"If we don't collect all of the information, we will never know whether it works or not," she told reporters.

While several aid groups welcomed the WHO announcement, some questioned whether the plan will actually work.

Stephan Goetghebuer from Doctors Without Borders said it will take some time to organize clinical trials for the untested Ebola treatments.

"Our priority right now is to save the lives of people affected today, and it is unclear how quickly a trial of a new treatment could feasibly be organized," he said in a statement.

Canada to donate experimental vaccine

Hours after the WHO announcement, Federal Health Minister Rona Ambrose announced that Canada will be donating between 800 to 1,000 doses of an experimental vaccine that is being developed by scientists at the Public Health Agency of Canada.

The final number of donated vaccines will depend on the specific amount required for clinical trials, the agency said in a statement.

As well, a small supply of the vaccine will be kept in Canada, in the event it is needed for "compassionate use" in this country.

The vaccine, VSV-EBOV, has never been tested in humans, but has shown promise in research using animals, the agency said.

Ambrose also announced that the agency will be giving $185,000 to the WHO to help the global-health agency boost infection control and surveillance measures in the affected regions.

Drug supplies in question

Kieny said on Tuesday that it was important to not give the impression that the experimental drugs can be rushed to patients right now, as supply will likely be tight.

One experimental Ebola treatment called ZMapp has only been given to two American aid workers.

Dr. Kent Brantly and Nancy Writebol were infected with Ebola while working in Liberia. They both consented to receive the treatment, which is based in part on Canadian research.

The treatment was also offered to a Spanish priest who died on Tuesday. It is not clear if he received ZMapp before his death.

The company that develops ZMapp, San Diego-based LeafBio, said it had exhausted its supply of the drug, and experts said it could take months for another small batch to be made.

Infectious diseases expert Dr. Neil Rau said that although the Americans who received ZMapp are reportedly improving, there is still no proof that the drug is working.

"We've jumped to the assumption that the treatment given to Writebol and Brantly actually worked. We have no proof that it actually worked," Rau told CTV News.

In the meantime, public health officials will rely on standard infection control practices and quarantines to try and contain the outbreak.

The Ebola outbreak now involves four countries: Guinea, Sierra Leone, Liberia and Nigeria.

According to the WHO, there have been 1,848 cases as of Aug. 9. Since early March, the outbreak has claimed at least 1,013 lives.

With a report by CTV News' Medical Specialist Avis Favaro and Senior Producer Elizabeth St. Philip and files from The Canadian Press