A Breakthrough Cure for Ebola | Hacker News Reader

A Breakthrough Cure for Ebola

genome.fieldofscience.com

112 pointsihodes24 comments

The problem with Ebola is not really the cure. It's the factors around the disease that make it very difficult to cure.

First of all, Ebola is very similar to malaria. In all the areas that Ebola occurs, malaria also occurs, and it would be impossible for normal people to tell the difference. Malaria is a very common disease and the infected usually just take anti-malarial tablets and wait it out, which I assume they also do for Ebola.

By the time the symptoms diverge away from Malaria - i.e, the blood starts coming out, it's very difficult to cure. The people taking care of the infected person would have already been sick, and the original person would already be pretty close to death, that is unlikely that this treatment will help him.

I'm not sure when the treatment starts getting effective, but the described article starts treatment 30 minutes after the introduction of the virus. This will not happen in the real world. In the real world, treatment is likely going to start when the disease is pretty advanced all round.

Ebola is also a disease that is going to stay in underdeveloped isolated areas. It puts the person in bed so quickly that the person would hardly have a chance to infect anyone in countries with proper hospital systems.

The diagnoses equipment for Ebola are also not so accurate, and the response for it is expensive, so false scares are going to have more of a damage than the actual disease.

From the article itself:

This is a breakthrough not only because it may give us a cure for an uncurable, incredibly nasty virus, but also because the same method might work for other viruses, and because we have woefully few effective antiviral treatments.

The exciting thing is not that we have a potential cure for a rare[1], exotic[2] virus. The exciting thing is the technique and its potential applicability to other viruses.

[1]http://en.wikipedia.org/wiki/List_of_Ebola_outbreaks

[2] Part of the reason they're probably using Ebola is to get DoD funding (ie in the anti-biowarfare space)

Unfortunately, this piece is affected by typical science journalism that hypes up everything a titch. Fundamentally, this treatment is a textbook case of applied RNA interference (RNAi). While it is really awesome to see RNAi used in a medical context (these nano-payloads of RNA are really interesting), all the caveats of RNAi apply.

If the virus has a highly variable DNA sequence, different RNAi sequences will need to be designed, validated, and grown up in lab for each viral strain. Viral strains will need to be identified upon infection so the right RNAi sequences are used, which can increase time until treatment. We won't be seeing this technique used on a highly variable virus like HIV or the common cold anytime soon, because these viruses mutate incredibly quickly within the host.

Yes, typical journalist hype by this hack Steven Salzberg (http://en.wikipedia.org/wiki/Steven_Salzberg). Ah, "the Director of the Center for Bioinformatics and Computational Biology at the University of Maryland, College Park"? Well nevermind.

And while yes, RNAi has been around for a while, nothing like this has been done with the technology. This is a breakthrough.

Iddo Friedberg has a nice review of the paper as well

http://bytesizebio.net/index.php/2010/05/29/a-cure-for-ebola...

The key for me is this part

"this is the first time that siRNA treatment has been shown to work in primate models of a human disease."

That's a big deal under any circumstances.

You shouldn't speculate without doing a bit of homework first. The Ebola virus is reported to have a mutation rate that is approximately 100 times slower than the influenza virus, making it more like other human viruses, which also tend to mutate slowly. (HIV is an extreme outlier with its extraordinary mutation rate.) The RNAi sequences used in this experiment will likely work for quite a few years.

The investigators plan to do safety tests in humans next, but they have some preliminary data on safety this is positive.

Fascinating to see that they started with the most interesting virus rather than the most commercially valuable virus. Stopping the common cold is probably worth 100 times more money, but stopping Ebola is more scientifically interesting. Kudos.

It may have more to do with the fact that monkeys cannot contract rhinovirus. Therefore, no test subjects with moderately similar physiology.

That and Ebola is cool.

The cold might mutate too fast for this to work well.

More power to them. But notice they have defense funding. As the article hints, right now, if someone with Ebola got on a plane to Cairo or Johannesburg, billions of people would die. That’s not worth much in the $10 × 1,000,000,000 people way of the common cold, but it will get you enormous government grants and a huge amount of prestige.

Wikipedia makes a city-disaster seem unlikely. It is not much airborne, and isolation-nursing prevents spread.

Unlikely.

I just checked the wikipedia article, and the Ebola virus is not naturally transmitted as an aerosol (http://en.wikipedia.org/wiki/Ebola#Transmission). It is transmitted through bodily fluids, including supertiny droblets but that won't effect more than the ten people closest to the infected person on that plane, and before they have a chance to infect anybody else the worlds medical system will have indentified and dealt with the case.

In addition, the virus kills within 2-21 days, so it is unlikely to have time to spread to that many people from each source.

Therefore, this won't be the new black death, but that won't stop the media from comming all over the story.

There has actually been a case of an Ebola-carrier travelling by plane to Johannesburg, back during the Gabon outbreak in 1996. The only other person he infected was a nurse who had come into direct contact with some of his blood. She died a short while later, but infected nobody else.

Ebola is a frighteningly deadly virus, so this sort of research is very encouraging, but its lack of an aerosol delivery mechanism and its quick mortality cycle both mean that it will likely never cause an epidemic on the scale of Bubonic Plague.

The common cold's actually a tough one. There are so many different viruses that cause "the common cold" and an anti-viral would probably only work on one of them.

Just putting together a clinical trial would be incredibly expensive because of the difficulties in picking out patients who have the virus your drug treats while they're still early enough on in their illness to be treatable. I may be wrong, but I thought that there actually were some early phase trials of a drug to treat rhinovirus, but they were stopped because of logistical difficult and expense.

The common cold is caused by a variety of viruses and strains that identifying all the possible DNA sequences to target would overwhelm researchers for years. This treatment is incredibly targeted, which requires the exact target DNA sequence of the pathogen to be known, siRNA snippits designed and tested against that sequence, and then for the siRNA to be put into a drug.

Ebola was probably chosen because it is a rather stable virus and has only relatively few serotypes.

Actually there are over 100 strains of cold viruses, many of which were completely sequenced and reported in a paper in Science last year.

But as to why this group of scientists chose Ebola: they have been working on Ebola for over 20 years, so they made that choice long ago. Every human virus has a scientific community of experts who study it.

All known strains of Ebola virus have very high mortality rates, ranging from 25% to 90%, and there is no cure.

This is not entirely true, the Ebola Reston strain is seemingly harmless to human beings.

http://en.wikipedia.org/wiki/Reston_ebolavirus

"They report a 100% success rate, although admittedly the test group was very small, just 4 rhesus monkeys.

"This is a breakthrough"

I'd hold off on the word "breakthrough" until

a) there is replication of the result in a larger sample by other investigators

and

b) there are some human trials of the treatment. The technique is interesting, but it needs more study.

http://norvig.com/experiment-design.html

b) might take a while. I can't see anyone voluntarily getting infected by Ebola, and there haven't been any outbreaks recently.

"Ebola has very few genes - only 8. One of its genes, called L protein, is responsible for copying the virus itself. Two others, called VP24 and VP35, interfere with the human immune response, making it difficult for our immune system to defeat the virus."

Genomics and nanomeds, now that's amazing!

run directly towards the slowest virus, since it has a wounded leg? (sorry, couldn't resist :-)

In all seriousness, though, this is very exciting. I wonder how easily this technique could be adapted to work on other viruses, like HIV.

It would probably only work while HIV was active, but not when it hides inside a T cell. (HIV is very unusual in that regard.) It's called "HIV latent reservoir" and it's the reason nothing has worked. This is unlikely to change that.

Pardon my ignorance, but if an individual's HIV is 'active' (I'd be curious to know more about the definition of active in this case) does that mean that's the case across every cell of their body, or might some cells be active and others inactive?

Active means the virus is either attempting to infect a cell, or copying itself. When it's inactive it just sits in the cell doing nothing.

Some are active, some are not.

I believe it starts with lots of active viruses, then many go dormant, while others continue infecting. Then pretty much all of them go dormant, while slowly activating in small numbers over a long time (20 years even).

It's sort of a war of attrition, the virus kills immunity (T) cells slowly, over time. It's possible to prevent it from killing cells (which will then recover to normal levels), but the virus keeps hiding in other cells.

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