Because Kent Brantly is a physician who has watched people die of Ebola, there was an especially chilling prescience to his assessment last week, between labored breaths: "I am going to die."
His condition was grave. But then on Saturday, we saw images of Brantly's heroic return to U.S. soil, walking with minimal assistance from an ambulance into an isolation unit at Emory University Hospital.
"One of the doctors called it 'miraculous,'" Dr. Sanjay Gupta reported from Emory this morning, of Brantly's turnaround within hours of receiving a treatment delivered from the U.S. National Institutes of Health. "Not a term we scientists like to throw around."
"The outbreak is moving faster than our efforts to control it," Dr. Margaret Chan, director of the World Health Organization, said on Friday in a plea for international help containing the virus. "If the situation continues to deteriorate, the consequences can be catastrophic in terms of lost lives, but also severe socioeconomic disruption and a high risk of spread to other countries."
In that light, and because Ebola is notoriously incurable (and the strain at large its most lethal), it is overwhelming to hear that "Secret Serum Likely Saved Ebola Patients," as we do this morning from Gupta's every-20-minute CNN reports. He writes:
Three top secret, experimental vials stored at subzero temperatures were flown into Liberia last week in a last-ditch effort to save two American missionary workers [Dr. Kent Brantly and Nancy Writebol] who had contracted Ebola, according to a source familiar with details of the treatment.
Brantly had been working for the Christian aid organization Samaritan's Purse as medical director of the Ebola Consolidation Case Management Center in Monrovia, Liberia. The group yesterday confirmed that he received a dose of an experimental serum before leaving the country.
In Gupta's optimistic assessment, Brantly's "near complete recovery" began within hours of receiving the treatment that "likely saved his life." Writebol is also reportedly improved since receiving the treatment, known as zMapp. But to say that it was a secret implies a frigid American exceptionalism; that the people of West Africa are dying in droves while a classified cure lies in wait.
The "top-secret serum" is a monoclonal antibody. Administration of monoclonal antibodies is an increasingly common but time-tested approach to eradicating interlopers in the human body. In a basic monoclonal antibody paradigm, scientists infect animals (in this case mice) with a disease, the mice mount an immune response (antibodies to fight the disease), and then the scientists harvest those antibodies and give them to infected humans. It's an especially promising area in cancer treatment.
In this case, the proprietary blend of three monoclonal antibodies known as zMapp had never been tested in humans. It had previously been tested in eight monkeys with Ebola who survived—though all received treatment within 48 hours of being infected. A monkey treated outside of that exposure window did not survive. That means very little is known about the safety and effectiveness of this treatment—so little that outside of extreme circumstances like this, it would not be legal to use. Gupta speculates that the FDA may have allowed it under the compassionate use exemption.
A small 2012 study of monoclonal antibody therapy against Ebola found that it was only effective when administered before or just after exposure to the virus. A 2013 study found that rhesus macaques given an antibody mix called MB-003 within the 48-hour window had a 43 percent chance of surviving—as opposed to their untreated counterparts, whose survival rate was zero.
This Ebola outbreak is the largest in the history of the disease, in terms of both cases and deaths,
729 887 known so far. As Chan warned in her call for urgent international action, the outbreak is geographically the largest, already in four countries with fluid population movement across porous borders and a demonstrated ability to spread by air travel. The outbreak will be stopped by strategic quarantines and preventive education, primarily proper handling of corpses. More than 60 aid workers have become infected, but many more will be needed to stem the tide.
Dr. Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Disease (NIAID), is encouraged by the antibody treatment.
"Obviously there are plans and enthusiasm to expand this," Fauci told me. "The limiting factor is the extraordinary paucity of treatment regimens." Right now the total amount available, to Fauci's knowledge, is three treatment courses (in addition to what was given to Brantly and Writebol).
NIAID did some of the original research that led to the development, but this is owned by Mapp Biopharmaceuticals. "They are certainly trying to scale up," Fauci said, "but I've heard that their capability is such that it's going to be months before they have a substantial number of doses, and even then they're going to be limited."
"We're hearing that the administration of this cocktail of antibodies improved both Dr. Brantly and Ms. Writebol, but you know, we don't know that," Fauci said, noting the sample size (two) of this small, ad hoc study. Proving effectiveness would require a much larger group of patients being compared to an untreated group. "And we don't know that they weren't getting better anyway."
This post is updated from a version originally published August 4.
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