Heinz Feldmann in scrubs and a rain jacket outside one of the tents in Monrovia.

Heinz Feldmann in scrubs and a rain jacket outside one of the tents in Monrovia.


Confronting Ebola: A virologist in Liberia's hot zone

Virologist Heinz Feldmann has spent most of his career studying the deadly Ebola virus at research institutes in Germany, Canada, and the United States. He is now at the Rocky Mountain Laboratories of the National Institute of Allergy and Infectious Diseases in Hamilton, Montana.

Feldmann has co-developed one of the vaccine candidates that is scheduled to be tested soon and has helped contain several Ebola outbreaks in the past. On 8 September, he returned from 3 weeks in Monrovia, Liberia’s capital, where he ran a diagnostic lab for a treatment center operated by Doctors Without Borders (MSF). This interview has been edited for clarity and brevity.

Q: What was your impression of the situation in Monrovia?

A: The first impression was actually that nothing is wrong. The part of the city we were in, outside the center, was pretty calm. But when you get to the Ebola ward, that impression turns. It is a disastrous situation. There are a lot of sick people hanging around, trying to get in, but the ward is just not big enough. They have to turn obviously sick people back into the community because there are no beds. I think we would need at least five to 10 times the capacity in Monrovia. The city is totally overwhelmed by the number of cases and the outbreak.

Q: What about yourself? How afraid were you of getting Ebola?

A: As a lab worker, I feel extremely safe. We're very well trained for this. You would really have to have a catastrophic event happen in order to get a high-risk exposure. Having said that, you would be surprised what you sometimes get. You get tubes wrapped in gloves, including the needle, or broken glass vials. Those kinds of things you have to watch out for.

People working for MSF, the clinicians, the nurses, that is a different story. They have a much higher potential of being exposed because they have to deal with the patient. Patients are like virus factories producing up to a hundred million virus particles per milliliter of blood, and a patient is unpredictable; a patient could cough, could spit at you, vomit on you, or even become aggressive and attack you. So these people really have the highest risk and have the highest burden. 

Q: But isn’t there a risk of contracting the virus off the job as well?

A: If you move around, you never know who is infected and who isn't. This is the bigger problem for me personally. You have to basically avoid contact with local people, which is very difficult because these are friendly people, they like to touch each other.

I actually think passing through the airport on my way out was the highest risk. They are bringing hundreds of people into a very confined space with a lot of direct contact, so if you get a patient into that environment, you are going to have exposures. It is a ridiculous situation. Also, they are checking your temperature three times before you get into the airport, but if you look at the people that do this kind of work, they don't really know how to use the devices. They are writing down temperatures of 32°C, which everybody should know is impossible for a living person. All the checks they do are completely useless because they are done by people who are not well trained or overwhelmed by the number of passengers. It is just a disaster, and it needs to be fixed.

Q: What did you do in Monrovia?

A: We came to Liberia with the mission to go to a smaller town up in the northern part of the country, very close to the border with Guinea and Sierra Leone. There is a hotspot up there. But when we got to Monrovia, MSF just started to operate this tent structure that they call ELWA3, an Ebola treatment center on the outskirts of the city. It had 120 beds at the time we left, but they are scaling up to 400, that is their goal.

Patients are lying on mattresses on the ground in tents. ELWA3 is currently not set up for intravenous support, so it is only oral rehydration and certain supportive medications, antimalarials or antibiotics, if appropriate, to treat secondary infections. At the time we got there, there was also only limited capacity to confirm the infection and separate those who are actually sick from Ebola from others. MSF was desperately looking for laboratory support. So the mission lead decided that we would stay with ELWA3.

Q: So you started doing diagnostic tests?

A: In the first 3 weeks we basically did nothing but testing for Ebola using PCR. It's very simple diagnostics. Just Ebola: yes or no? But it was overwhelming at the beginning. Among the new submissions, the positivity rate was up to 90% or even higher.

Q: You have seen many outbreaks of Ebola. What is different about this one?

A: We still believe it was caused by a single introduction of the virus into the human population. What is different is that we see a lot of human-to-human transmission chains. Normally there are a few, three or four maybe. But now there are many more chains of transmission.

Q: There has been speculation that the virus could mutate or has already mutated to spread more easily. How likely is that?

A: I don’t think there is any data right now to support that. If you look at the virus sequence, it falls within the normal range of Zaire Ebola strains. Of course any of these mutations could have a dramatic effect, which we don't know right now. But there is nothing obvious that would point to a more transmissible, more virulent virus, or a change of transmission route.

You can speculate in every direction, of course, but I think it should be fact-based, it should be data-based, and I think it makes absolutely no sense to bring in aerosol transmissibility as a potential. I think this is really not helpful, unless you have data to support that.

Q: Is there any genetic data from Ebola strains in Liberia?

A: Right now our diagnostics is largely based on sequence data from Sierra Leone. But it has become very, very important to get the sequence of the currently circulating virus strains in Liberia to make sure that our assays are working properly. There is one gene target that we are not using anymore because we were missing cases.

Q: At the moment, you are storing some blood samples from patients in Monrovia, but you’re not sending any samples out to be sequenced?

A: No, and that is a very common situation. It goes into the discussion of intellectual property. In my view the owner of the specimen is the patient, first of all, and then the country, so the ministry of health or the government. So in order to bring samples out of Liberia there needs to be some kind of agreement in place that this is allowed, and that takes time. People are working on a memorandum of understanding and I think and hope we're going to get it very quickly. But you cannot just export clinical samples without proper permission.

Q: So you haven't done any science yet?

A: I think at the moment this is strictly outbreak response, and there is no time to do research. But I hope that once we have reached the peak and are on the downside—I cannot tell you when that will be—that we will get the opportunity to do some more clinical research that will help us to better design treatments and prophylactic measures and to better design patient management. Right now I don’t think it's time.

Q: You’ve done a lot of research and helped develop one of the candidate vaccines that is going to be tested now. Is it going to help end this epidemic?

A: At the moment the focus is very much on experimental vaccines and treatments. Those things would help but I don’t think they will show an immediate impact on this outbreak. Really, outbreak control measures should be the key.

Q: I would have thought you were more positive about your vaccine candidate.

A: Of course, I would like to see it used. We just have to be realistic. How many people would you have to immunize to see that impact? I think with the amount of doses that are currently available, this is just a drop in the ocean. I don’t know how many people you would have to reach. In measles, people talk about a necessary coverage of more than 90%.

Q: But measles is much more infectious than Ebola. Models suggest that if only half the people are protected from Ebola by a vaccine, that could already stop the outbreak.

A: Right, but how many doses do you need to achieve 50%? I think we just don't have the doses at the moment. Without the proper production I think it is just an almost useless discussion. I have no idea of how quickly production could be scaled up to produce enough doses.

Q: But many people are expecting this outbreak to take many more months. Doesn't that mean that vaccines could play a role even if they are months away?

A: I agree we certainly need to move on and consider it. But I would warn people to expect an immediate impact on this outbreak because that is not realistic. We could maybe see a little impact. There is a lot of discussion of using a vaccine to protect health care workers. And maybe there is enough to do that. But is that ethical? Who do you pick? Who do you protect?

*The Ebola Files: Given the current Ebola outbreak, unprecedented in terms of number of people killed and rapid geographic spread, Science and Science Translational Medicine have made a collection of research and news articles on the viral disease freely available to researchers and the general public.

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