The fruit bat is said to be a common carrier of the Ebola virus.
The consensus among local scientists and scholars who recently weighed in on experimental drug use in the treatment of two Ebola-infected Americans is that, under the circumstances, it was morally the right call.
“In this case, what’s unusual is that the proper treatment is a new one, had not been tried on humans in any way,” said Michael Kalichman, a professor and director of the UCSD Research Ethics Program, who noted extensive drug trials with animals is standard practice in first combating disease outbreaks like those from Ebola.
Kalichman pointed out that the federal Food and Drug Administration (FDA), which protects public health through regulation of food and drugs including vaccines and biopharmaceuticals, has an “escape clause” when it comes to using experimental drugs on humans.
“It’s FDA’s compassionate use policy,” he said, “which states that an (untested) drug can jump over hurdles and be used sooner in people on the assumption that trying it couldn’t make the patient any worse.”
Kalichman said the moral dilemma of using experimental drugs on Americans is that, if it makes them worse or is fatal, the decision to use it at all will be challenged.
“Our goal is to try and choose the least bad, and that’s not always easy,” he said, adding, “This is a tough situation ethically precisely because the choices you have are all bad.”
Kalichman said the international community will also question on whom the experimental vaccine was used.
“They’ll be asking: Why were two of the first people to get the vaccine from the United States rather than from Africa?” he said.
Ebola virus disease is an illness of humans and other primates fueled by an Ebolavirus. The disease, spread by contact with bodily fluids of infected people, is primarily prevalent in remote Central and West African villages. Symptoms of Ebola virus disease, also known as Ebola hemorrhagic fever, include fever, severe headache, muscle pain, weakness, diarrhea, vomiting, stomach pain and lack of appetite. Symptoms may appear anywhere from 2 to 21 days after exposure, though 8 to 10 days is most likely.
The Centers for Disease Control and Prevention says that it suspected or confirmed 2,240 cases as of Aug. 19, with 1,229 fatalities.
An Ebola virus disease epidemic is ongoing in West Africa, notably Guinea, Liberia, Nigeria and Sierra Leone. It is the most severe Ebola outbreak in terms of the number of human cases and fatalities since the discovery of the virus in 1976.
Typical outbreaks are reportedly 90 percent fatal; the current outbreak has resulted in a fatality rate of 60 percent.
Missionaries Kent Brantly and Nancy Writebol, the only two Americans known to be stricken with Ebola, were reportedly infected while caring for Ebola patients in Monrovia. Brantly was released from Emory University Hospital in Atlanta on Aug. 21 after a course of experimental drug treatment; Writebol was released from the facility on Aug. 19. Mapp Biopharmaceutical, a Sorrento Valley biotech firm, manufactures ZMapp, the experimental drug administered to the two. Shipments of the drug and an untested vaccine are reportedly on the way to Liberia.
Earlier this year, Mapp became part of a consortium working to create a "cocktail" of drugs to treat Ebola. The group of 15 institutions, lead by the Scripps Research Institute, was funded for $28 million over five years by the National Institutes of Health.
Erica Ollman Saphire, professor of the Department of Immunology and Microbial Science at Scripps, said using an experimental drug to fight Ebola may have been the only logical choice.
“You might be willing to take a chance on putting it into people infected with the Ebola virus if it has some minor side effects,” she said, adding, “What else are you going to do if they are infected with the Ebola virus other than give them fluids and Tylenol and hope for the best?”
Ollman Saphire said an even broader ethical question with treating Ebola victims with experimental drugs might be: Whom do you choose to give them to if there’s not enough to go around?
Ollman Saphire, who is researching the role proteins play in the fight against Ebola, said Mapp's antibody cocktail “works well in animal models.” Noting Ebola is still “not under control,” she said she is nonetheless encouraged that the battle against it will succeed. She noted that, unlike HIV, the Ebola virus does not remain in the victim's genome after infection. She also noted that Ebola symptoms appear much more rapidly than those of HIV, which can incubate for 10 to 20 years.
“Once you’re cleared of the disease,” she said,” you’re clean.”
“There may be some good news here in the long term,” Kalichman concluded, “that [ZMapp] may be a treatment that will be useful, though in the short term it’s been a challenge and stressful to figure out what to do. It’s easy to say they made the right decision if it worked out well. But if it doesn’t work out well — you can’t know that in advance.”