WATCH: Doctors are treating two infected Americans with an experimental Ebola serum, never before used on humans … and it’s working. Anthony Robart reports.
TORONTO – As the death toll from Ebola in several West Africa countries climbed to 887, a special plane was sent to evacuate the second American missionary who contracted the disease in a Liberia treatment facility. But the experimental serum being used on the Americans remains somewhat of a mystery.
Missionary Nancy Writebol’s plane is set to arrive in the U.S. Tuesday, where she will join Dr. Kent Brantly in an Atlanta hospital’s special isolation ward. Brantly has already received a unit of blood from a 14-year-old boy, an Ebola survivor, who had been under his care, said the aid organization he works for.
But neither organizations are commenting on further treatment for their workers or which serum is being used.
“It’s one of two possibilities,” suggested Dr. William Schaffner, a preventive medicine expert from Nashville’s Vanderbilt University.
“One is they could have taken some serum from a patient who has recovered from Ebola and used that in and of itself as the treatment. Or they could have …made a monoclonal antibody to Ebola and used that.”
Schaffner said a monoclonal antibody means producing an antibody in a molecular-biological fashion rather than taking it from a recovered patient.
“When we first heard that plasma or a blood transfusion had been given to these two patients—the plasma first to the lady, and then the blood transfusion to Dr. Brantly—we actually thought it was the first of the two possibilities: that these were harvested from survivors of Ebola and then infused into the sick patients,” said Schaffer.
“It’s strange that we don’t have a little bit more information yet about these details.”
Ebola has no vaccine or antidote, but international relief group Samaritan’s Purse (the group Brantly works for) said both workers were given the experimental treatment last week. Samaritan’s Purse has been providing emergency response to the Ebola epidemic in West Africa for months.
Writebol has received two doses of the serum and is showing marked improvement, said Palmer Holt, a spokesman for Service in Mission (SIM), the aid organization for which Writebol works.
“She is walking with assistance….strength is better…has an appetite,” wrote Holt in an email to Global News. When asked for details on which serum Writebol received, Holt said, “Medical questions not our area of expertise.”
Aside from using survivor plasma, there are two pharmaceutical companies that have been working with the U.S. military to help find a treatment for the drug, according to the International Business Times.
One is Canadian company Tekmira Pharmaceuticals Corp., which has already issued a statement that no one infected in the ongoing outbreak in West Africa has been treated with its drug, called TKM-Ebola.
Although there are a number of Ebola therapies in development, Tekmira’s is thought to be the furthest along in the regulatory process, though its clinical trial was recently put on hold by the U.S. Food and Drug Administration, which asked for additional data related to an inflammatory reaction seen when the drug was given at higher doses.
A second company working on the treatment is Mapp Biopharmaceuticals, developed with the help of tobacco leaves, according to the IB Times. CNN reports this is the company responsible for the drug administered to Writebol and Brantly.
A 2011 Arizona State University Report suggested Mapp’s plant-derived vaccine for Ebola “provided strong immunological protection in a mouse model” in which 80 per cent of mice given the treatment compounds survived.
Ebola, which causes hemorrhagic fever, spreads through close contact with bodily fluids and blood, meaning it is not spread as easily as airborne influenza or the common cold. Doctors and other health workers on the front lines of the Ebola crisis have been among the most vulnerable to infection as they are in direct physical contact with patients.
Schaffner said experimental serums have a long tradition in the history of the treatment of infectious diseases.
“If you have experimental, possibly therapeutic mechanisms or devices available, you can use them in individual patients in exigent circumstances—and this is the kind of emergent circumstance in which you might try something even in advance of a clinical trial.
“Desperate times demand desperate measures, and you do those things only in very controlled and limited circumstances.”
While the fatality rate for Ebola can be as high as 90 per cent, health officials in the three countries say the current crisis is killing at least 60 per cent of the people it infects in Africa.
But there have been some survivors. Schaffner said not many survivors have been studied, but the body would eventually rid itself of the virus for a complete recovery, unlike other diseases.
“You don’t create a chronic infection like HIV or sometimes Hepatitis B or Hepatitis C, where the patient for months and years continues to have the virus in the body with the risk of a resurgent disease; that does not happen with Ebola.
“It is not an auto-immune disease, and it is not a chronic infection.”
With files from The Canadian Press and The Associated Press
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