Follow Slashdot blog updates by subscribing to our blog RSS feed

 


Forgot your password?
Close
typodupeerror
×
Biotech Science

Ebola Vaccine Human Trials Begin 240

Posted by timothy from the flu-is-bad-enough dept.
securitas writes "The Washington Post reports on the first human to be injected with '100 trillion strands of synthetic' Ebola DNA. The DNA in the vaccine has been bioengineered by Vical to remove 'the part that triggers illness and the part that might allow the DNA to recombine with the DNA of some other virus.' The New York Times, AP via ABC and BBC all have stories about the new vaccine as the WHO reports 11 dead in a new Ebola outbreak in Congo this week. If you're interested in participating in the Ebola clinical trials, the NIH needs 27 volunteers. The study only has two. Best quote comes from the NIH vaccine center's nursing director: 'People freak out about Ebola.' Slashdot previously discussed an Ebola/HIV gene therapy."
This discussion has been archived. No new comments can be posted.

Ebola Vaccine Human Trials Begin More

Ebola Vaccine Human Trials Begin

Comments Filter:
  • Only one person, if I recall properly, from outside the Institute volunteered for this test; a landscaper.

    Of course, the gullible, sheeplike townspeople immediately asked him if he was going to bring "that durned ee-bow-luh" to their neighborhood. Sigh.

  • Thanks Hollywood (Score:2, Insightful)

    by Azghoul ( 25786 )
    Aside from any real danger that might be posed by this, I think Hollywood isn't doing the scientific community any favors (this season's 24, Outbreak, etc...).

    That said, I'd volunteer only if there were about 7 figures in hazard pay included. :)
    • That said, I'd volunteer only if there were about 7 figures in hazard pay included. :)

      That about sums it up for me as well. When I first heard about ebola (probably 4 or 5 years ago) it immediately took a place up there with crocidiles (which have 21+ days of memory to ambush you at the watering hole) among the scariest things in the world.

      The only thing that fascinated me about ebola was how it was such a mysterious virus, going seemingly dormant for months and then breaking out in unrelated areas. If

  • In other news... (Score:3, Funny)

    by JamesP ( 688957 ) on Wednesday November 19, 2003 @08:40AM (#7510096)
    has been bioengineered by Vical to remove 'the part that triggers illness and the part that might allow the DNA to recombine with the DNA of some other virus.

    Daryl McBride from SCO sais that this virus contains code property of SCO corporation.

    • Re:In other news... (Score:2, Interesting)

      by mongbot ( 671347 )
      Although I find kneejerk quips about SCO about as funny as cancer, your comment may have a grain of truth in it.

      Genetic Technologies, a small Australian firm, own patents [forbes.com] to "junk" DNA, a particular kind of DNA. More than 80% of the human genome is junk DNA, and I'd guess that a large portion of the ebola genome is junk DNA too. Intellectual property is just as bad for biology as for software development, it seems.

  • An alternative... (Score:5, Insightful)

    by in7ane ( 678796 ) on Wednesday November 19, 2003 @08:41AM (#7510107)
    Wouldn't a better idea be to seek volunteers in Congo - in high risk areas? Possibly near the area of the outbreak (/as soon as the next one starts so as to also try and prevent the spread of infection). Otherwise are they planning to infect the volunteers with Ebola... and don't expect anything to go wrong?

    On the unethical side - if anything goes wrong it's not like the settlement in Congo will be remotely what it's in the west. People are probably less "freaked out"/don't understand the dangers, so volunteers would be easier to find. -- not that I support these reasons,

    • The NY Times article mentions this (Score:5, Interesting)

      by mattbot 5000 ( 645961 ) on Wednesday November 19, 2003 @09:49AM (#7510553) Homepage
      The very last line of the article, hanging out all by itself:

      Scientists might test the vaccine in an outbreak of Ebola under emergency conditions.

      There was a very intruiging article in the New Yorker awhile back about just this subject: testing HIV/AIDS vaccines and other pharmaceuticals on Africans. Unfortunately it's not available online, and I wouldn't want to go into any more detail and risk being -1 Offtopic. But here's a short summary of the article [kaisernetwork.org].
    • Otherwise are they planning to infect the volunteers with Ebola... and don't expect anything to go wrong?

      No. From the linked NIH page seeking volunteers:

      In the new trial, volunteers will receive three injections over two months and will be followed for one year. Volunteers will not be exposed to Ebola virus.

      Presumably, this test is somewhat akin to a Phase 1 clinical trial--the researchers want to know if there are any adverse responses to the vaccine itself, and perhaps get some idea about an approp

      • Ultimately, at a later stage, this will have to be tested with exposing people (volunteers) to the virus after the vaccination. Or at least I assume this is a requirement (in stage III?) for this to be deemed an effective vaccine.

        I'll blame my lack of clarity on not reading the article.

        • Re:An alternative... (Score:3, Interesting)

          by kesuki ( 321456 )
          phase 1 and 2 determine the suitable dosage, potential side effects, etc... phase 3 and 4 trials involve the more extreme situation of testing on people who may then be exposed. I've been involeved in a number of phase 1 and 2 trilals, and they generally are simple blood and/or urine measurements to see how the drug is absorbe and eliminated ina healthy patient... however, vaccine trials are much more potentially lethal than say, the type of trials i've done, since vaccines are generally made from the vi
    • I hate to be Mr. "slippery slope" but where does that kind of logic lead us. We would be exploiting the fear (real or immagined) of innocent and most likly poor people around the world instead of people who can make a fair and reasoned decision about entering the trial. Next we could improve the lives of the homeless by letting them enter clinical trials, I'm sure they could use the money.

      Why not substitute Ebola for say a new strain of Small Pox. Our goverment/corprate media machine will scare thousands o

  • Freaky (Score:5, Informative)

    by Mr_Silver ( 213637 ) on Wednesday November 19, 2003 @08:42AM (#7510120)
    Best quote comes from the NIH vaccine center's nursing director: 'People freak out about Ebola.'

    Well, given that ...

    Symptoms of the Ebola virus begin 4 to 16 days after the person is infected. Beginning symptoms are headaches, fevers, chills, muscle aches, and loss of appetite. When the disease progresses, patients experience diarrhea, rash, sore throat, vomiting,abdominal pain, and chest pain. The patients have limited kidney and liver functions, and have internal and external bleeding. The blood does not clot which can cause some serious problems. It cause the capillaries to bleed into surrounding tissue. The death of a patient occurs from 8-17 days after an infection.

    Source [teenoutreach.com]
    am I the only one that isn't surprised that people "freak out" about it?
    • Nah, it's more like Ebola turns them to jelly/jello.
      • What was that Dustin Hoffman, Morgan Freeman movie? Outbreak?

        something like "I cut this kid open and it looked like a bomb went off. All his organs were liquified."

        Not a pleasant way to die, by any stretch. This story about a bio-engineered, crippled DNA string virus sounds like the premise for a sci-fi novel:

        The DNA in the vaccine has been bioengineered by Vical to remove 'the part that triggers illness and the part that might allow the DNA to recombine with the DNA of some other virus.'

        ... what

        • I love the idea of 'crippling a virus' to keep people safe.

          Because it's not like evolution ever figured out a way to fix little genetic errors that hamper the survival of an organism.

          • Re:People freak out about Ebola? (Score:5, Informative)

            by MillionthMonkey ( 240664 ) on Wednesday November 19, 2003 @01:27PM (#7512329)
            "Little genetic errors"?

            They're removing two whole genes. Viruses only have several to begin with. Your own junk DNA is littered with the DNA of several thousand extinct endogenous retroviruses that have lost one or two critical genes. Ebola, being a filovirus, lacks reverse transcriptase and cannot even look forward to a career as a dormant junk DNA sequence.

            Your body sees the proteins expressed by the foreign DNA, creates antibodies, and that's it. The DNA does not replicate. Evolution requires successive copying operations (paired with natural selection) and does not apply to this process.

    • The bleeding is actually massive hemmoraging. Where the person bleeds from every orafice, including the their eyes, nose, and even their nipples. They begin to bleed from their rectum, cough up blood, and begin to bleed internally in the same way. The patient will then die from blood loss. The patient's blood contains tiny virus particles, which look like little black crystals in the blood.

      If you are lucky enough to survive this, and you are male, chances are your testicles will be destroyed, as the virus
      • If you are lucky enough to survive this, and you are male, chances are your testicles will be destroyed, as the virus attacks that area intensively.

        I know this may sound morbid, but I can't help it; I'm curious. What sort of condition does Ebola leave a survivor in? What sort of permanent damage is there? What kind of life is there for a person whose internal organs have been liquefied?

  • phase I trial (Score:5, Informative)

    by flynt ( 248848 ) on Wednesday November 19, 2003 @08:46AM (#7510142)
    This is a Phase I clinical trial. There are typically 3 phases to each clinical trial, with Phase III being "official" statistical study. Phase III is "gold standard" FDA phase, where you prove statistically that your treatment works.

    What is a Phase I trial? It is typically used to determine a maximum tolerable dose (MTD). And how is that done? Something called "dose escalation" is used. That means you start off with a very low dose typically given to 3 patients, and if no toxicities (bad things) happen, you raise the dose. You keep doing this until you observe two toxicities in two consecutive groups (typically). Many times the volunteers in Phase I trials are terminally ill and willing to try anything.

    If you are not terminally ill, perhaps waiting for the Phase III trial to join is the best bet, when they have already figured out the "maximum tolerable dose".

    • Re:phase I trial (Score:2, Informative)

      by poszi ( 698272 )
      If you are not terminally ill, perhaps waiting for the Phase III trial

      From the desctription [nih.gov] of the study

      A volunteer must meet all of the following inclusion criteria: (...) 8. In good general health without clinically significant medical history.

      So if you are terminally ill, don't bother. Come on. This is a vaccine. Vaccines are used on healthy people. They need to check the dose and side-effects. But it won't cause the disease.

    • I am not sure you are right. I thought phase I trials were always done on healthy individuals to find a basic tolerable dose, not a maximum tolerable dose (which I think is phase II).
      And phase III trials would mean testing on diseased patients, in this case, I guess it means receiving the vaccine and then be injected with ebola. I am not sure they would go that far here. They might vaccine thousands of people in potentially infected areas and see if any of the vaccinated locals get ebola.
      Anyway, vaccines

      • Re:phase I trial (Score:3, Informative)

        by flynt ( 248848 )
        I think your "basic tolerable dose" is the same thing. In this case, it is being performed on healthy individuals, since it is a vaccine. As for your theory on their Phase III trial, I bet you are right. Same thing with AIDS vaccines, they will see how many contract. Of course one of the most famous clinical trials ever was done on a vaccine, the Salk Polio Vaccine. The study was carried out on over a million young children and was the largest clinical trial ever, I believe it still is with possible ex
    • Phase III is "gold standard" FDA phase, where you prove statistically that your treatment works.

      Or, they approve it anyway, because they are not properly funded by the government who created them and are in a position of financial conflict of interest with the pharmaceutical companies.

  • Here Comes the Science... (Score:5, Informative)

    by Anonymous Coward on Wednesday November 19, 2003 @08:47AM (#7510153)
    Dude, I so knew that Biology degree would pay off.

    Ebola, as viruses go, is incredibly hard to contract. It lacks a carrier state, which means that contraction depends entirely on contact with infected secretions. Unless you're exchanging spit, bodily fluids, or blood, you're safe. As for the vaccine, stating that the "part that causes the virus to replicate" is removed if superfluous. A vaccine by its very nature is a pathogen modified to restrict replication, and in the case of Ebola, that means the ability to attch itself to your RNA, and manifest itself. The only danger from the vaccine would be isolated to the vaccine itself, NOT Ebola Hemorrhagic Fever.
    • Unless you're exchanging spit, bodily fluids, or blood, you're safe

      Doesn't that mean it can be transmitted by sneezing?

    • A vaccine by its very nature is a pathogen modified to restrict replication,

      Usually, but not always, true.

      Vaccines can be made using killed viruses, or weakened variants of viruses. Those vaccines are what you describe.

      Vaccines may also contain only components of a virus, rather than actual pathogens. Exposure to samples of the protein coat of a virus, for instance, can be used to stimulated antibody production. In this trial, apparently a sample of the viral DNA is being used.

      Finally, vaccines m

  • SCO (Score:2, Funny)

    by m00nun1t ( 588082 )
    We've found a use for SCO at last!!!!!!!!!!
    • Wouldn't the SPCA or something protest to the "Animal Testing" ? However, I don't dispute that as long as the source of said animals is the zoo that is SCO.

      SCO bashing aside, if this works, would it mean that we would finally have a sure fire vaccine for all viruses? I.e AIDS etc. By simply using the same process as above, but with diffrent viruses?

    • What as? A control group to be infected with the real Ebola virus to give them something to compare the vaccine test subjects with? With all the other crap they are haemoraging at the moment a few pints of blood and liquified organs probably wouldn't even be noticed.
      • More like a control group to give the placebo vaccine to before exposing to the real virus.
        No wait, that's spammers.

  • There's no Ebola exposure here (Score:5, Interesting)

    by vykor ( 700819 ) on Wednesday November 19, 2003 @08:54AM (#7510181)
    This clinical trial doesn't involve the exposure of testers to live Ebola virus. That would be wholly unethical given the lethality of the disease. No trial of that sort would have any chance of being approved. This study just tries to prove the vaccine's safety for human use.

    In the article it specifically notes "Volunteers will not be exposed to Ebola virus." No live virus was involved in the manufacturing process either.

    Because of the ethical problems involved in any human clinical trial with real live virus, they'll probably use the "two-animal" rule in that if it protects at least two animal species from the virus, it's considered valid. Once this study proves safety, then it'll be licensed. The real trial would begin if they ever use this in the next Ebola outbreak.

  • Here's a Volunteer (Score:3, Funny)

    by Anonymous Coward on Wednesday November 19, 2003 @08:54AM (#7510185)
    > ...the NIH needs 27 volunteers.

    I nominate Darl McBride!

  • So Who's Up For It? (Score:2, Interesting)

    by Anonymous Coward
    If someone here voulenteers and provides proof I'll PayPal them $20.

    So who else is with me? Let's see how much we can get here!

  • Artificial virus - artificial response? (Score:3, Insightful)

    by Pastey ( 577467 ) on Wednesday November 19, 2003 @08:56AM (#7510198)
    The first question that popped into my mind was, "How on earth do you test wether or not this vaccine has worked?" I mean, it's entirely man made - no DNA from the Ebola virus was used, just man made copies. So who's to say we got it right? The only true indicator would be to expose a test subject.

    From the article:

    "Because it would be unethical to expose humans to Ebola to test the vaccine's efficacy, scientists will simply compare their immune responses with those that proved effective in monkeys and other animals. Much larger human studies will eventually be conducted to provide final proof that the vaccine is safe for large populations."

    The only real proof of whether or not this is effective or not will be when it's distributed to those running a daily risk of infection in the Congo. I understand that before that stage it must be proven safe, but imagine if it fails. That would be a big setback for what sounds like a innovative and creative technique (ie - man made DNA mimicing a pathogen).


    Considering the potential and the amount of time and money invested, I'm hoping this meets with success. The benefit when applied to other rampant diseases is enormous.

  • nothing compared to things like smallpox (Score:5, Interesting)

    by AssFace ( 118098 ) <`stenz77' `at' `gmail.com'> on Wednesday November 19, 2003 @08:59AM (#7510209) Homepage Journal
    My uncle is a quiet and reserved guy. He works with highly infectious agents as his job - space suits and special rooms - that whole deal.
    For Christmas back in the day he gave me The Hot Zone by Richard Preston. I read it that weekend and then asked him about ebola - my uncle is one of the team that they send to the part of the world that is having some new outbreak - ebola is one of his specialties.
    He was in the Peace Corps in Zaire back when then first discovered ebola, and even met his wife that way when they were both in the same tent recovering from malaria.

    He said ebola was really nothing to worry about since it killed its host so fast. He said that it was indeed a bad thing if you ever got it, and it does need to be contained, but it dies very quickly outside of its host, and it kills its host too quickly.

    He also noted that AIDS isn't particularly impressive either. It dies quickly outside of the person as well.

    He isn't discounting the viruses by any means - just in terms of the scary stuff that he works with, he wasn't as scared by those and they are on different containment levels than other things.

    He mentioned smallpox as being horrible.

    I am now finishing up Richard Preston's The Demon in the Freezer and I must say that it is very interesting (his books all seem to be written in a way that you can finish them in an unnerving weekend).

    Smallpox in itself is scary stuff, and then the bioengineered completely resistant smallpox is really freaky.
    Anthrax is nothing compared to this stuff - anthrax can kill its host, but it is not contagious from that sick host - if someone with anthrax coughs in the same room as you, you don't then get anthrax. Whereas one person with smallpox can infect an extremely large area around them very quickly - and they don't necessarily show any signs of having it but are capable of spreading it in the first few days of being infected.

    Personally, I would much rather die of a drug overdose while having sex with supermodels than have to die of any of these viruses.
    Hopefully the chances of either being my final exit are equally slim.
    • Personally, I would much rather die of a drug overdose while having sex with supermodels than have to die of any of these viruses.

      Supermodels, plural? I wish I half your imagination -- I figured sex with one supermodel was good enough to die for!

      Kidding aside, thanks for the interesting comments about your uncle's work.

      -kgj
    • met his wife that way when they were both in the same tent recovering from malaria.

      Through sickness and in health, and in that order.
      It's actually quite romantic.
    • "Impressive" to your uncle must mean something along the lines of "capable of destroying all humanity." Which is, I admit, one possible definition. A bit sick, though.

      Ebola is so scary because of how little [who.int] would have to change for it to become "impressive". Ebola is an incredibly efficient killer, way more than smallpox's 30%-50% fatality rates. The Ebola that's around right now would be nothing compared to that incubated in an (infectious) victim for 6 months before the victim bled out. You could see epi
    • At the risk of slashdotting a really good book, I humbly offer an absolutely excellent read on the Soviet development of pathgenic weapons: Biohazard, by Ken Alibek [nih.gov] (the former first deputy chief of Biopreparat, the Soviet state pharmaceutical agency that developed and manufactured biological weaponry).
  • "Ebola testing? Nonono...I thought you said Ricola testing!"

  • Disproportional Scare (Score:3, Insightful)

    by 4of12 ( 97621 ) on Wednesday November 19, 2003 @09:19AM (#7510307) Homepage Journal

    Given all the hype about bio terrorism and the wrenching effects of this hemorrhagic fever, the public tends to think of Ebola as a foremost danger.

    Meanwhile, AIDS, which was a big scare two decades ago, has not become an widespread epidemic in developed nations despite having been around a couple of decades, takes a long time for mortality when properly treated with the latest expensive drugs, and "seems to be something that only gays and drug users get". In the public mind, it's not considered much of a danger.

    But AIDS is devastating [dfl.org.za] Africa these days.


    6-10 Kenyan soldiers die weekly; 80% infected [bbc.co.uk]
    AIDS orphans outcast [allafrica.com]
    • But AIDS is devastating Africa these days.

      Very true -- Africa is currently the living hell of continents. Meanwhile, the disease is threatening to do the same around the world, e.g.:

      South America [cnn.com]: "Latin America has yet to experience a full-blown AIDS epidemic, but the disease is spreading from high-risk individuals to the general population ..."

      Asia [cnn.com]: "Asia is at risk of facing the world's worst AIDS epidemic if urgent preventative measures are not taken ..."

      -kgj
      • And Russia [themoscowtimes.com]: U.S. government-sponsored think tank, has identified five countries of strategic importance that have large populations at risk of HIV infection. Russia is one of those five, along with India, China, Nigeria and Ethiopia.

        And India [belfasttelegraph.co.uk]: India's hidden Aids epidemic: virus to infect 25m by 2010

  • Ebola is not a threat to many people (Score:3, Insightful)

    by cyman777 ( 631050 ) on Wednesday November 19, 2003 @09:26AM (#7510346)
    From a global point of view it does not make sense to invest too much into research on Ebola as it only causes problems for a view people (who are extremly poor creatures that need help of course, don't get me wrong!).

    Putting the money into Malaria related projects would benefit more humans, as Malaria is one of the biggest killers in Africa, esp. amoungst children. HIV would be next on this list as whole generations are at risk and actually dying because of HIV.

    But surely it is interesting to do research on Ebola and with the mediy hype about it you can even become famous...

  • Uhm...no (Score:4, Interesting)

    by cybermace5 ( 446439 ) <g.ryan@macetech.com> on Wednesday November 19, 2003 @09:32AM (#7510402) Homepage Journal
    Back during the big anthrax scare, they were doing vaccine trials at the medical school at Vanderbilt University. My sisters had a few friends who were lured by the mad cash (about $200 or $500) and became guinea pigs...apparently some of them got sick, and from what I understand the vaccine had a certain risk of causing a heart condition.

    So don't volunteer for these studies for the cash; only do it if you are prepared to become a medical sacrifice for the good of the world. Or something like that.
  • 'People freak out about Ebola.'

    I don't know about the rest of the readers, but when my skin starts to sweat blood, I tend to go Freaking crazy, not just freak out.
  • and do TRY not to melt into a puddle. It would terrible PR.
  • I liked Roger Daltry better when he was a singer. This actor and reporter stuff he's doing just isn't as good.

  • Typical rich providing for the rich (Score:3, Interesting)

    by dorfsmay ( 566262 ) on Wednesday November 19, 2003 @10:11AM (#7510729) Homepage

    Ebola scares us in the west because we don't have a cure, and death is nearly certain. We, the rich people in the west, feel threaten and therefore spend the money on looking for a vaccine for it, but consider this:

    Very few (less than a 100) die of ebola each year. The biggest killer in the world is tuberculosis. Why don't we look for a vaccine against it ? Oh yeah that's right if somebocy gets tuberculosis in the west, we cure them with antibiotics - the people who die because of tuberculosis are in the poor countries... who cares.

  • This is why I hate science... (Score:3, Funny)

    by c4ffeine ( 705293 ) <[moc.liamg] [ta] [enieff4c]> on Wednesday November 19, 2003 @10:34AM (#7510921)
    For the past 5 years of my life, Ebola has been one of the coolest things in existence. It's a virus with a 90%+ fatality rate, no cure, etc, liquified within a week, etc. Imagine weaponizing that baby, making it airborne... take that, popular culture!

    Anyways, why must science ruin nature's best things? We've killed off pretty much every large predator and made most kick-ass diseases extinct. What's the fun of that?

    To make matters worse, we're probably pissing off God (or whatever runs this universe as root). We've defeated his ways of killing people! No more lightning, plague, floods, wars where that many innocent people are killed, and "fire and brimstone", aka meteorites, can't be THAT far off...

  • Unfortunately, (Score:3, Funny)

    by frenetic3 ( 166950 ) <houstonNO@SPAMalum.mit.edu> on Wednesday November 19, 2003 @11:19AM (#7511330) Homepage Journal
    We tried reaching him for comment, but his face was in the middle of falling off, and he was having difficulty breathing.

  • why ebola though? (Score:4, Insightful)

    by caveat ( 26803 ) on Wednesday November 19, 2003 @11:43AM (#7511531)
    besides the horrible horrible pathology of the disease, ebola isn't really a "biblical plague" virus - it tends to self-contain due to the clear symptomatology leading to rapid isolation and the relative difficulty of transmission. Now, if it became airborne and contagious like rhinoviruses, then we have a serious problem; it hasn't, perhaps we'd be better off spending the time and effort to find a vaccine for that most devilish of virii, HIV?

    disclaimer: i am not a virologist/geneticist familiar with the details of ebola's function, so i can't say that figuring a vaccine for ebola isn't a conceptual breakthrough that will allow a whole new class of vaccines...but if it isn't, this just seems like mental masturbation, a cure for a nonexistent problem.

    • Actually, it tends to self contain due to it's rapid lethality.

      But somebody could turn it into a nasty bioweapon simply by lengthing the incubation period; if you can communicate it for two weeks before onset of symptoms, you can infect a hell of a lot of people who will die three weeks later.

    • Some reasons:
      1. It's really, really deadly. Currently, it's not so contagious, but that sort of thing has been known to change for other viruses.
      2. It's easier to vaccinate against than HIV. HIV is a real
      moving target - it mutates a lot. It also mounts an attack against the immune system itself, which makes it hard to defend against.
      3. There is already a version of Ebola that is (probably) transmitted through the air - "Ebola Reston". For some reason, it doesn't affect humans, but it's incredibly deadly to
  • I'm a healthy white male, and have lost nobody I know to the Ebola virus, but I think any disease this deadly should have a cure as soon as possible.

    I'm young enough to still pretend I'm invincible, and I don't have a fear of needles. :-)

  • How this all works... And I mean all of it. (Score:5, Informative)

    by nicodemus05 ( 688301 ) <nicodemus05@hotmail.com> on Wednesday November 19, 2003 @01:26PM (#7512323)
    Ok... There seem to be a lot of misunderstandings about how this works. I'll see if I can clear some of them up. Much of the following is a simplification, so please don't flame me about technicalities. The on topic stuff is at the very bottom, the rest is background for those who want it.

    What is a Virus? How does it work?

    A virus is a protein sheath (called a capsid) covering genetic information. The protein sheath varies in size and shape, the most famous being the T4 Bacteriophage (picture [sc.edu] on the bar on the left). Simply put, the genetic information can be in the form of RNA or DNA. The virus latches onto a host cell and injects its genetic material through the plasma membrane.

    Viruses all have different strategies at this point, depending on their structure and target cells.

    The most insidious, the retroviruses (of HIV fame), incorporate their genome into the host cell's. When the host cell copies its own DNA, in the process of normal cell division, it copies the code for the virus. Each daughter cell resulting from this mitotic division carries the virus latent in its own DNA. They now, in their normal life cycle, become factories for the retrovirus, pumping out more and more protein encased genetic sequences. Propagation is very thorough.

    A simpler virus might only borrow the mechanisms of the cell to replicate itself. The virus would use DNA polymerases and associated enzymes to copy the genome for the viral offspring and RNA polymerase to transcribe mRNA molecules to translate to proteins for the viral capsid. The baby virii are then assembled (the DNA wrapped in the protective capsid) and they exit the cell. Sometimes this results in the death of the cell, other times it does not. The virus doesn't much care whether the cell survives once it has been copied.

    The body, however, doesn't take kindly to its cells being hijacked. It doesn't matter if the viral infection doesn't result in the death of any cells. An infection is inefficient; a virus uses a lot of the cell's energy, energy that could be better spent in normal functions. Here's where the immune system comes in.

    How does my immune system protect me from Ebola ?

    Proteins are the real workhorses in cellular biology. As far as molecules go they're about as diverse as it gets; almost everything a cell does it does with proteins. A protein is coded for by a gene, a sequence of base pairs in the genome. When we make a protein we tend to make more than one at a time (one type of protein, multiple copies). One or more copies in the set get paired with another protein. This other protein, called MHC, has the sole purpose of escorting its pair to the surface of the cell and holding it there. The surface of the cell has hundreds of proteins of various types sticking out. When a virus instructs a cell to make its proteins the cell follows normal procedure and sends some of them to the surface.

    The immune system is incredibly complicated. A subset of it is the T cells, which are themselves divided into two groups, Helper T Cells and Cytotoxic T Cells. Cytotoxic T cells are easier to describe; they're often called assassin cells or natural killer cells. Their purpose is to kill anything foreign that they find in the body. The Helper T Cells each have proteins on their surface (called antibodies) that recognize one target (called an antigen). They wander around, checking out all of the other cells in the body, looking for a match. If a Helper T Cell was looking for EVP-1(Evil Virus Protein 1) it would ignore every cell that didn't display EVP-1 on its surface.

    If they find a match they know that the cell is infected with Evil Virus, and they signal for the Cytotoxic cells to come do their job. They also reproduce. So imagine you have a million Helper T Cells with random antibodies on their surface. You're betting on the one cell that is looking for EVP-1 into a cell that happens to be infected with a Ev

  • in the good ol' medical tradition, the developers of the vaccine should've been the first to take it.

Slashdot Top Deals

If you aren't rich you should always look useful. -- Louis-Ferdinand Celine

Close