In the absence of official confirmation about how the two American patients with Ebola are being treated, rumor and speculation filled the void.
First were the reports that the blood serum of a teenage Ebola survivor may have saved Dr. Kent Brantly and Nancy Writebol, who contacted the deadly disease in Liberia while working with the Christian aid organization Samaritan’s Purse.
The latest news centers around an experimental “secret serum” called ZMapp. Already, CNN’s Dr. Sanjay Gupta has proclaimed that the medicine “appears to have worked.” Sadly, Dr. Gupta seems to be over-promising. Here’s why. Treating Ebola with the blood of a survivor: The science behind the first alleged treatment — using the blood serum of a survivor to cure those who are suffering — is the subject of controversy in the Ebola research community, said Dr. Thomas Geisbert, a professor of microbiology and immunology at the University of Texas Medical Branch. “Back in 1995 during the large outbreak of Ebola Zaire virus in the Democratic Republic of the Congo, there were reports that convalescent serum was used from people who survived Ebola to treat people who were infected,” he said. A small case series report about the treatment involving eight patients was published in the Journal of Infectious Diseases. Only one of the eight people died- a fatality rate much lower than the then-outbreak, which killed some 80 percent of those infected.
Unfortunately,
however, the serum theory was not confirmed by later studies. “When we
tested that hypothesis in a lab, and took convalescent blood from
animals who survived and gave it to Ebola-infected animals, they all
died,” said Dr. Geisbert. “There was the belief that most of those
patients treated were in the process of recovering anyway.” Yesterday,
the “secret serum” called ZMapp emerged as the primary treatment of the
Americans. This is an antibody therapy developed by several stakeholders
— Mapp Biopharmaceutical, Inc. and LeafBio in San Diego, Defyrus Inc.
from Toronto, the U.S. government and the Public Health Agency of Canada
— to treat Ebola. It’s made up of a cocktail of monoclonal antibodies,
which are just lab-produced molecules that mimic the body’s immune
response. To create these molecules, scientists gave mice Ebola proteins
and watched the animals’ immune systems respond. After identifying the
antibodies that fought off the disease in mice, they created almost
identical antibodies from plants for use in humans. The idea is that,
when given to Ebola-infected people, the drug will boost their immune
system so that they too can eliminate the virus. But this drug has never
undergone testing in people, only monkeys. The data on the efficacy of
ZMapp in monkeys has never even been published.
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