Ebola Researchers Have A Radical Idea: Rush A Vaccine Into The Field
Today, the World Health Organization concludes a two-day meeting to discuss a radical idea: bringing a vaccine into the field without having tested its effectiveness.
Traditional means of containing Ebola — such as isolating people who are infected with the disease and tracing the people they've come into contact with — aren't working fast enough to get ahead of the epidemic. So the question is: Will giving an experimental vaccine to willing volunteers help contain the disease or put people at greater risk?
Dr. Adrian Hill, director of the Jenner Institute at Oxford, says the urgency of the Ebola situation has led to throwing traditional timelines "out the window."
He's part of a team of doctors at Oxford University, the National Institutes of Health and the pharmaceutical company GlaxoSmithKline who are rushing to create one of several new Ebola vaccines.
Hill says their vaccine could be ready to give to health care workers as early as late November. That would be an extremely fast pace compared with the typical timeline for developing a new vaccine.
Moncef Slaoui, who's in charge of vaccines for GlaxoSmithKline, says his company has been working on a malaria vaccine for 31 years. While that may be an extreme example, five to 10 years is considered average.
A typical vaccine trial starts small. Scientists inject about 20 healthy volunteers and closely monitor their health for six months to a year. They test volunteers' blood every other week and check for signs like fever or swelling, which could indicate the vaccine is unsafe. Eventually, the scientists add more volunteers to the study. And they test higher doses.
Ebola researchers at the NIH, Oxford and GlaxoSmithKline are compressing those steps to meet the November deadline. They plan to look at volunteers' blood for antibodies they know are protective against Ebola. But before vaccinated people come into contact with the disease, developers can't know for sure that the vaccine works.
For that kind of certainty, they'd need to set up a trial with thousands of people in places where Ebola outbreaks are occurring. One group would get the real vaccine; the others would get a placebo.
By comparing the two groups, developers could begin to understand whether their vaccine is effective. But Ebola vaccine researchers are debating whether to bypass this phase of testing because so many lives are at stake.
Nancy Kass, a public health ethicist at Johns Hopkins University, says that the best way to study a new vaccine is to test it against a placebo. But the situation in West Africa complicates that decision. "The problem is that all of our norms change when thousands of new cases of Ebola are happening all the time and 50 to 60 percent of these people are dying. That changes the rules about what we have to lose when we try something new," she says.
Some scientists think moving forward without a control group of people who don't get the vaccine isn't worth the risk — notably Anthony Fauci, director of the National Institute of Allergy and Infection Diseases at NIH.
"If you did it in the way where you never could tell whether it worked well, worked a little, didn't work at all, or actually made people worse ... you could actually propagate a disaster," he says.
Fauci has experience with vaccines that appeared to be safe during the initial phases of testing but turned out to be ineffective and even dangerous. Most recently, an HIV/AIDS vaccine was deemed safe but in later tests "increased the risk of HIV infection in the people who were vaccinated," he says.
WHO says it supports the use of unproven interventions to treat Ebola. And GlaxoSmithKline isn't waiting for testing to be completed. It's producing 10,000 doses of the vaccine. That's much more than would be needed for a trial.
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Transcript
ARUN RATH, HOST:
The first man diagnosed with Ebola in the U.S. is now in critical condition. Texas Health Presbyterian Hospital in Dallas reports that Thomas Eric Duncan's condition has worsened. The director of the CDC, Thomas Frieden, spoke on NBC's "Meet The Press" this morning. He says an Ebola outbreak in the U.S. is still very unlikely.
THOMAS FRIEDEN: The bottom line here is we know how to stop it. It's not going to spread widely in the U.S. for two basic reasons. We can do infection control in hospitals. And we can do public health interventions that stop it in its tracks.
RATH: The situation in West Africa is much different. There Ebola is spreading so quickly that the World Health Organization has been discussing a radical idea to fight it, using a new unproven Ebola vaccine. But as NPR's Caitlin Dickerson reports, that move raises serious ethical and safety questions.
CAITLIN DICKERSON, BYLINE: Traditional means of containing Ebola, like isolation and tracing contacts, aren't working fast enough. So scientists are proposing taking a vaccine into the field without having tested its effectiveness.
ANTHONY FAUCI: It is conceivable that the only thing that really turns this thing off is a vaccine that works.
DICKERSON: Anthony Fauci directs the National Institute of Allergy and Infectious Diseases at the National Institutes of Health. He's part of a team of doctors at the NIH, Oxford University and the pharmaceutical company GlaxoSmithKline that are rushing to test one of several experimental Ebola vaccines.
This is something that makes scientists uncomfortable - taking an unproven vaccine, giving it to a vulnerable population and hoping it will prevent people from contracting Ebola.
ADRIAN HILL: All the traditional paradigms have just gone out the window. And that's because of the urgency of the situation.
DICKERSON: Doctor Adrian Hill directs a vaccine research institute at Oxford.
HILL: We thought given there's no other vaccine and there's no drug available for Ebola, we might have a crack at this and see if we could get it to the affected region in just a few months.
DICKERSON: Just a few months. To understand how fast that is, you need to know how long it can take to develop a new vaccine. Doctor Moncef Slaoui is head of vaccines and development at GlaxoSmithKline.
MONCEF SLAOUI: Let me just give you a benchmark. We have been working on our malaria vaccine for 31 years now.
DICKERSON: Malaria is an extreme example. But vaccines often take five to 10 years to develop, sometimes even longer. A typical vaccine trial starts small. Scientists inject about 20 healthy volunteers and test their blood every other week. They check for swelling, irregular heartbeat, high blood pressure, fever, anything that would indicate the vaccine is unsafe. Eventually, the scientists add more volunteers and test out higher doses.
The Ebola researchers are compressing those steps and hope to know if their vaccine reacts safely in humans by late November. But they wont know if it works until vaccinated people come in contact with Ebola. For that, the scientists would need to give it to thousands of people in the outbreak setting. Some of them would get the real vaccine and some a placebo.
And this is where the Ebola vaccine could break form in an unprecedented way. Scientists are debating whether to bypass the placebo phase entirely and distribute the vaccine to healthcare workers right away. Nancy Kass is a public health ethicist at Johns Hopkins University.
NANCY KASS: Thousand of new cases of Ebola are happening all the time. And 50 or 60 percent of these people are dying. That changes the rules about what we have to lose when we try something new.
DICKERSON: Even if the rules change, some scientists think moving forward without a control group of people who don't get the vaccine just isn't worth the risk. Anthony Fauci from the NIH is one of them.
FAUCI: Because if you did in the way where you never could tell whether it worked well, worked a little, didn't work at all or actually made people worse, you could actually propagate a disaster if you do that.
DICKERSON: Fauci says the vaccine could be distributed to healthcare workers in the region. But he argues it should still be part of a clinical trial.
FAUCI: We have experience, most recently with HIV/AIDS, where a vaccine looked good in an animal. It was safe in trials. And it actually increased the risk of HIV infection in the people who were vaccinated.
DICKERSON: The World Health Organization says it supports the use of unproven interventions to treat Ebola. And GlaxoSmithKline isn't waiting for testing to be completed. It's producing 10,000 doses of the vaccine. That's much more than would be needed for a trial. Caitlin Dickerson, NPR News. Transcript provided by NPR, Copyright NPR.
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