Canadian firm Immunovaccine Inc. announced Monday that four macaque monkeys that had been exposed to a fatal dose of the Ebola virus survived after receiving an experimental vaccine.

Immunovaccine added that two other monkeys that were exposed to Ebola but were not given the vaccine died.

The monkeys that survived received two doses of the vaccine before being exposed to a fatal dose of the Zaire strain of Ebola, "believed to be the most lethal among Ebola viruses and ... responsible for the current Ebola virus outbreak" that has killed nearly 1,500 people in West Africa, the company said in a press release.

"Based on this high efficacy" the statement said, "Immunovaccine is exploring a potential development program for an Ebola virus vaccine with various organizations."

The tests were conducted by the U.S. National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health.

The firm added that the vaccine tested on the macaques is based on its so-called DepoVax technology, which is being developed to treat different infectious diseases.

"These preliminary results are encouraging and support the continued evaluation of an Ebola vaccine in DepoVax, potentially leading to a clinical study," Immunovaccine CEO Marc Mansour said. EFE