Calls for testing experimental Ebola vaccine in West Africa intensifies
TORONTO – The largest Ebola outbreak in history is defying the containment efforts of affected countries and international response teams, leading to calls from some quarters to use experimental drugs or vaccines to try to stop the deadly virus.
But a number of experts – including the scientist who led the work on a Canadian-made Ebola vaccine – say deploying untested tools in the current West African outbreak could be disastrous.
They say taking such a risky gamble could further erode local trust in the response teams, undermine their efforts and even endanger them. And if anyone were to have a bad reaction to one of the experimental therapies, it could jeopardize years of expensive and painstaking work spent developing tools with which to fight Ebola and its cousin, the Marburg virus.
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“I get emails basically every second day from someone either asking ‘Is there something that you’re planning?’ or ‘Shouldn’t you?’ And I know I’m not the only one getting those emails,” says Dr. Heinz Feldmann, an Ebola expert who heads the laboratory of virology at the U.S. National Institute of Allergy and Infectious Diseases’ Rocky Mountain Laboratories in Hamilton, Mont.
While most of these discussions are happening within scientific circles, the director of Britain’s Wellcome Trust recently aired the issue publicly. Dr. Jeremy Farrar, an infectious diseases expert, has questioned why the therapies that are furthest along in the developmental pipeline aren’t being used. He suggests if this outbreak were occurring in the developed world, there would be no debate.
“Imagine if you take a region of Canada, America, Europe and you had 450 people dying of a viral hemorrhagic fever. It would just be unacceptable – and it’s unacceptable in West Africa,” Farrar says.
He notes the Canadian-made Ebola vaccine – a project Feldmann led a decade ago when he worked at the National Microbiology Laboratory in Winnipeg – was released under emergency use provisions in 2009 when a German researcher pricked herself with a needle containing Ebola virus. She survived, but it was never clear if it was because of the vaccine or because she was not infected.
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“We moved heaven and earth to help a German lab technician. Why is it different because this is West Africa?” Farrar asks.
A small community of researchers, mostly based in Canada and the United States, has been working for years on vaccines and drugs to protect against or treat these viruses, which are among the deadliest known to humankind. The viruses are transmitted through contact with bodily fluids. People caring for the dying – or preparing their bodies for burial – are often infected.
With little to offer medically, the main job of response teams is to break the chains of transmission by figuring out who is infected and isolating them. But these efforts are often met with distrust. Rumours emerge that the Western doctors are harvesting organs; people hide cases or flee – extending the range of the epidemic.
World Health Organization says the current outbreak – the first in West Africa – has seen 844 cases in three countries, and 518 deaths. That’s already virtually double the size of the next largest outbreak, in Uganda in 2000. And this outbreak isn’t anywhere near over.
A number of vaccines are in various stages of development. Studies done in non-human primates suggest they could both prevent illness and improve survival chances if given after infection. There are also a number of therapies in the works, including antibody combinations that look promising in animal testing.
But the researchers have always been stymied by the challenges of getting regulatory approval for these interventions, which cannot follow the traditional pathways to licensure. Most drugs or vaccines can only make it to market once large scale studies show they are both safe and effective. But the only way the world will learn if Ebola and Marburg vaccines and drugs work is by using them in an outbreak – a reality rife with ethical concerns and logistical problems.
In the current context, with response teams struggling to gain the co-operation of fearful locals, word that experimental treatments were to be used could further exacerbate an already taxing situation, says Dr. Armand Sprecher, of Medecins Sans Frontiers (Doctors Without Borders). The organization warned recently that the outbreak was out of control and said it was stretched to its limits.
“I would hate to cause more problems than we solve in the short run,” Sprecher says. “Right now people are at their wits end just to deliver the care that we’re able to provide.”
Dr. David Heymann, a professor of infectious diseases at the London School of Hygiene and Tropical Medicine, says after this outbreak is contained, the WHO, Ebola researchers, the countries they work in and the countries which are prone to these epidemics need to sit down and plan how they will deploy and test these therapies the next time. They need to have the study protocols ready to be signed.
“It would be unethical to roll it out now, in my opinion,” says Heymann, a former assistant director general at the WHO and a member of the team that responded to the first Ebola outbreak in 1976.
Feldmann agrees with Heymann’s idea. Over the years he has been frustrated by the inability to get these needed tools approved. But he says he has been persuaded by friends working on the current response that using untested and unlicenced medical interventions now would be a mistake. One was blunt about how badly awry such an effort could go.
“He said ‘Anything injectable would be a disaster.’ He thinks the rumour that we’re just spreading the disease is going to be out there before we even start,” Feldmann says.
“I think as bad as it sounds – and I really don’t feel good about saying this – I have the feeling they have to find a way to end this one without (experimental) therapy.”