Researchers have developed vaccines and treatments that show promise in fighting Ebola in animals, so is the outbreak a good opportunity to test them in people?+ READ ARTICLE
On Monday, National Institutes of Health immunologist Dr. Anthony Fauci told CBS This Morning that his research team is working on a vaccine to prevent Ebola, which is completely effective in monkeys, and will be tested in humans in September. And he’s not the only one developing a treatment for the deadly disease. The question is: Should experimental treatments be rushed into practice, given the breadth of this outbreak?
For the nearly 1,400 people who have been infected with Ebola, there isn’t much they can rely on to help them battle the vicious virus. Because the virus hones in on the liver and disrupts the formation of liver cells, which affect blood clotting, people eventually die from shock, when their blood pressure drops too low due to the build up of microscopic clots in the vessels. The only thing that can improve survival is intervening early with proper hydration and nutrition to keep the circulation strong.
But there are several promising interventions in the pipeline, all of which have been very effective in fending off the virus in monkeys, who experience the same symptoms and disease course as humans. Most of these vaccines and drugs, however, have not passed even the Food and Drug Administration’s (FDA) more lenient standards for therapies against exotic viruses like Ebola.
Should drugs get rushed to market?
Normally, companies must prove that a therapy or drug is safe and effective in people through rigorous clinical trials, but no trial would allow participants to ethically get infected with Ebola, given that it’s mortality rate ranges from 50% to 90%. So the FDA recently approved a different pathway for such products in which companies can first prove that the disease progresses similarly in an animal model as it does in people, and that the product is safe when tested in healthy people.
Only one of the Ebola vaccines, which uses the cold virus as a vector to introduce the Ebola antigens, has reached the second stage, and public health officials are likely reluctant to introduce them widely in west Africa given their untested status and the fear and suspicion of western medicine that already makes the outbreak so difficult to contain.
“To bring a strictly experimental approach to this population – most people think that’s not a good idea, and not doable,” says Dr. Heinz Feldmann, chief of the laboratory of virology at the National Institute of Allergy and Infectious Diseases.
In order to even consider using such unapproved drugs in the crisis, they have to be requested. So far, neither the governments of the west African countries affected, WHO, nor humanitarian groups like Doctors Without Borders have done so. If they did, then regulatory officials in the U.S. would discuss whether they could be provided on a “compassionate use” basis.
Testing the vaccine on a human
That happened in 2009, when a German researcher received the shot after accidentally pricking herself while working with Ebola in the lab. The immunization she got was developed in 2005 by Feldmann and his colleagues, including Thomas Geisbert, professor of microbiology and immunology at the University of Texas Medical Branch at Galveston. The vaccine both protects against Ebola infection and treats those who are recently infected with the virus.
While it’s not clear whether the lab workers was actually infected – she got the shot 40 hours after the accident – she did not develop symptoms and did not show evidence of the virus in her blood.
“There’s just no financial incentive”
Feldmann says there are other strategies that look equally promising — but taking the next step of testing the products in people is proving more difficult, says Geisbert. “Globally, [Ebola] is not a huge problem in terms of infectious diseases in general. It’s devastating and sad for the people involved but it’s a small market for big pharmaceutical companies. There’s just not a financial incentive to develop a drug or vaccine.”
Unfortunately, it often takes outbreaks like the current one in west Africa, which is the largest in Ebola history (see Infographic: Ebola By the Numbers), to ignite interest in developing treatments. That, Feldmann notes, and the fear that a virus like Ebola could be used as a form of bioterrorism. “The fact is that biothreat countermeasure activities are what pushed multiple governments to do this work,” he says. Some of that investment may pay off in public health benefits, however, since a bioterror event is essentially an intentional and concentrated outbreak. Geisbert recently received a $26 million grant from the National Institutes of Health to study the three strategies, including in combination, to take the interventions to the next step.
And while an outbreak might seem like an ideal opportunity to test new treatments, it may actually be of little use, and may even do more harm than good. “My concern is that if you give the treatment to people in late stage disease, and if the person dies, then everybody is going to blame whatever was given,” says Geisbert. “If the person survives, you may never know if the product worked because it was somebody who was going to survive anyway, without the drug.”
Feldmann agrees. “People like me and others who have worked for years in vaccines and countermeasures are frustrated. But on the other hand, we don’t want to make a step that isn’t well thought through, and ruin the whole approach in the future.”