As work speeds up to develop a vaccine that could help stop the spread of Ebola in West Africa, a researcher from the University of Maryland, Baltimore (UMB) was in Geneva, Switzerland late last week.
Dr. Myron M. Levine was attending an emergency World Health Organization (WHO) meeting of more than 200 experts, and preparing to co-lead a site in Mali that will conduct clinical trials of the treatment, as Technical.ly Baltimore reported last week.
The raging epidemic has killed 1,900 people, which surpasses the death toll of any outbreak since the disease was discovered in 1976, according to the WHO. Amid the increasingly rapid spread, health officials are racing to develop treatment that could combat the disease. At the conclusion of the meetings on Friday, officials expressed hope that the vaccine could be ready as soon as November.
Fast-tracked trials to prepare what researchers hope will be the the first-ever Ebola vaccine are being organized by an international consortium of organizations, which received a $4.6 million grant for testing and manufacturing of the drug. Samples of the vaccine, developed by the National Institutes of Health (NIH) and pharma company GlaxoSmithKline, are currently en route to the University of Oxford, England, where the first round of testing will be undertaken on 60 healthy people.
If the Oxford trials are successful, UMB’s Levine will then receive samples at a site in Bamako, Mali. Along with UMB adjunct Dr. Samba Sow of Mali’s Center for Vaccine Development (which is a joint project of the Malian government and UMB), Levine will oversee testing on a total of 40 healthy people.
Technical.ly Baltimore talked to Levine and Sow from Geneva about the makeup of the vaccine, the trial process and why a treatment is so badly needed. (Editor’s note: The transcript has been edited for length and clarity. Emphasis added.)
Technical.ly Baltimore: Before we get to the vaccine, can you talk a little bit about what you’re hearing from healthcare workers and people on the ground about the urgency of having something to combat the spread of the disease?
Samba Sow: This is the first time we have seen Ebola in West Africa. We are obviously all very scared. It’s very worrisome for the community, for the government and more importantly health workers. Contamination is very fast. The front line people, like the health workers, are the most concerned.
In terms of control activities, in all West African countries, we have a team of health workers controlling each border. Every transportation — public and private — we stop passengers, look for potential sick persons and make sure that there are no suspected cases. This is going on everyday 24 hours a day, 7 days a week.
Myron Levine: What’s happening in West Africa is simply changing the dogma. It’s making a rewrite of the chapter of Ebola epidemiology. It’s simply unheard of what’s going on now. It’s an enormous epidemic. Instead of being just in very isolated rural areas, and then pretty quickly nipped in the bud, it’s reached urban slums in the major cities in Liberia and Sierra Leone, and also in urban areas of Guinea. It’s billowing. There’s never been anything like this.
The case fatality is about 50 percent, so 1 of every 2 people with Ebola disease confirmed die. 10 percent of those deaths are healthcare workers, doctors, nurses, auxiliaries, people who are required to keep a hospital or health center running. Because of that, understandably, the health workers are afraid for their own lives, and for their families. And so in these very poor under-resourced countries, three of the very poorest in the whole world, right at the bottom of development, countries that have been wracked by civil war and coup d’états, in these countries that have very broken healthcare services, when you have doctors and nurses not coming to facilities that are underserved to begin with, it’s a disaster. It’s a public health crisis.
TB: What is the timeline for your phase of the trial to begin?
SS: If I have my vaccines tomorrow, I could start on all my trials. It has to go through many many steps. We are estimating to start, maybe last week of September, or the first week of October.
TB: When did work on this candidate vaccine begin?
ML: Everyone agrees that if there were a vaccine with certain characteristics, it could make a difference. It would make a difference because the spread of Ebola occurs under three main scenarios, one of which is at hospitals and health centers. So if we had a vaccine and we knew it would work with a single dose and we know it would work quickly, looking to the future, that would be an important public health tool. We’re trying to find out whether these latest two candidates from the vaccine research center at NIH may fit this bill.
They have done a lot of work, more than a decade, they’ve been looking at different types of Ebola vaccines. This one is probably the best thing that they’ve ever had. It really looks good. It’s a very elegant vaccine design. It takes a virus called an adenovirus that causes usually a mild respiratory infection, either in humans or in primates. They take a chimpanzee adenovirus — which will not cause disease in humans, so that’s a safety factor. They did some genetic engineering to remove some genes from the virus, so this virus can’t replicate. It cannot continue to grow when it’s inoculated into a human or a monkey. So that’s further safety. Because it can’t grow, you have to give a pretty big dose to stimulate a protective immune response. But these particular chimp adenoviruses seem to be doing the job. These so-called live vector, or carrier, viruses carry a gene from the Ebola virus that tells the adenovirus how to make an Ebola protein, and if the animal can make an immune response to that one single protein of the Ebola, you prevent Ebola disease. This is pretty recent that they’ve gone step-by-step-by-step-by-step to reach this point.
TB: Given their fears and the importance of their work on the front lines, will healthcare workers be given the vaccine first?
ML: That’s what we’re doing in Mali. You do Phase I and Phase II in healthy individuals, and in this case it’s healthy adults because the overwhelming number of cases are adults. So, if we have to do that anyway, why not make it the health workers, who would take care of an Ebola case? If one of the suspect patients that Samba examined and took a specimen from turned out to be a confirmed case, then it would go into his isolation unit, and all of his people would be at risk. They would wear protective clothing, they would do their best, but wouldn’t it be great if we could have them immunized as well? And if, that’s an if, this vaccine happened to work in humans like it worked in monkeys, then we’re on our way to something.
TB: Who would receive the vaccine after healthcare workers?
ML: What we would envision is we would try to gather all of the safety and immune response stimulation data that one needs to be able to move into places like Guinea, Liberia. There’s only a limited number of doses, but we would envision doing that first. One could also envision doing these safety immunogenicity studies in even contacts of cases who are taking care of those cases. But first and foremost is healthcare workers because, whoever gets sick, they need a lot of intensive care with Ebola. And if you don’t have doctors and nurses in hospitals. and health centers because they’re afraid of the disease, that’s a crisis. We may be able to change that, at least that part, with the first sets of doses that will be available over let’s say the next 6-8 months.
The way this epidemic is raging is anyone’s question what’s going to happen. There have been a few isolated cases in Nigeria. There was a case in Senegal. But we just can’t predict, and all it takes is a bit of bad luck.
TB: The International Consortium (which includes UMB) that has been assembled to speed the development of this vaccine has been called unprecedented. Can you talk more about the progress of this effort and what makes it unique?
ML: It’s the first time that everybody’s gotten together and done this, this quickly. So far, it’s working. We won’t know for sure until we get the first doses into people in West Africa. Samba and I each were tracked down by the World Health Organization, I think it was either Aug. 10 or 11, and here we are looking at getting the vaccine into people in September, in West Africa, having the clinical protocol for this study. The protocol was made very quickly, having it reviewed by three different ethics committees in Mali, having it reviewed by a WHO ethics committee, and by a University of Maryland, Baltimore ethics committee. Having arrangements to move the vaccine from NIH to Oxford, where they will take responsibility for then shopping it to us. Doing all this to make it the shortest regulatory oversight possible. This is historic how quickly it’s occurred.
But it’s an important dress rehearsal because we know for example that sooner or later there will be another bad influenza pandemic. History tells us that will happen. And we’re going to have to learn how to do this on a much, much bigger scale when that happens.