The National Microbiology Laboratory in Winnipeg sent Spain and Norway one treatment course each of ZMab, a monoclonal antibody cocktail developed at the lab.
The supplies of the drug were what is called laboratory grade and had been made for research in animals. Drugs used in humans are made to the rigorous standards known as current good manufacturing practices or cGMP.
It is uncommon to treat humans with laboratory grade drugs, an expert who asked not to be named acknowledged.
"Yeah, it's unusual. But it's an unusual time," the expert said.
A spokesperson for the Public Health Agency said the product was supplied to Spain and Norway on the request of the two countries.
Spain was looking for an experimental drug to treat a nursing assistant who was infected while caring for one of Spain's two cases, both priests who contracted Ebola while working at a treatment facility in West Africa. And Norway was seeking treatment for a Norwegian nurse who was infected while working for Medecins Sans Frontieres — Doctors Without Borders — in Sierra Leone.
"The experimental treatment was donated on compassionate grounds to help treat health-care workers infected with Ebola," the Public Health Agency said in an emailed response to questions.
"Canada has a limited amount of experimental treatment remaining available at this time. All remaining inventory will be kept in Canada for research purposes or for compassionate use by Canadians as needed."
It is not clear whether either health-care worker has received the treatment.
Media reports from Spain have presented a conflicting picture about whether the woman there actually received the drug. A Spanish news website, Lainformacion.com, quoted Fernando Simon, head of Spain's Centre for Health and Emergency Alerts, as saying ZMab was not given to the woman because of concerns over possible side-effects.
ZMab is a precursor to ZMapp, the first experimental drug used in this outbreak. There were very limited supplies of ZMapp — fewer than a dozen treatment courses — available when the outbreak began. Those were exhausted over the summer.
Both experimental products are cocktails of three monoclonal antibodies — antibodies that each target a specific site on the exterior of the Ebola virus.
ZMapp is an amalgam of monoclonals from ZMab and another cocktail, MB-003. ZMab was created by scientists at the Winnipeg lab and MB-003 was made by scientists at the U.S. Army Medical Research Institute of Infectious Diseases in Fort Detrick, Md.
Both showed good efficacy in testing in non-human primates. But Dr. Gary Kobinger, the head of Special Pathogens at the Winnipeg lab, felt that there might be a more effective combination that could be created from the pool of six antibodies. His team in Winnipeg tried and tested the various combinations until they came up with ZMapp.
The product has been licensed to U.S. biotech company Mapp Biopharmaceuticals.
The current Ebola outbreak in West Africa is the worst the world has ever seen, with the World Health Organization projecting the case count will top 9,000 sometime this week.
The agency's Dr. Bruce Aylward said Tuesday that the case count has been growing at a rate of about 1,000 a week in recent weeks, but that could rise to between 5,000 and 10,000 per week by early December. Aylward said the current count of known cases rests at 8,914 cases and 4,447 deaths.
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