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Science

Examining Influenza 27

Posted by michael from the but-not-too-closely dept.
Wolffman writes "University of Wisconsin-Madison scientists have solved a long-standing puzzle about how the influenza virus assembles its genetic contents into infectious particles that enable the virus to spread from cell to cell, scientists have opened a new gateway to a better understanding of one of the world's most virulent diseases."
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Examining Influenza More

Examining Influenza

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  • Kawaoka (Score:3, Interesting)

    by GrimSean ( 545405 ) on Thursday January 30, 2003 @12:51PM (#5189684) Homepage
    Yoshi Kawaoka [wisc.edu] who is the principle person behind this research, also works with Ebola [wisc.edu]. I would be interested to know if the Ebola virus uses a similar method of infecting host cells, as I believe both it and the Influenza A virus have a similar incubation period.

    The article states that a single RNA strand is responsible for recruiting the other seven, which then work together to produce more virons. I'm curious as to whether it is that RNA strand which has to mutate in order for the virus to jump from species to species (such as from birds to humans). Perhaps this could lead to a new innoculation for birds that would prevent their viral infections from jumping ship to us.

    • Re:Kawaoka (Score:3, Informative)

      by Simon Field ( 563434 )


      The article says "What's unique about this virus is that its genome is fragmented into eight RNA segments".

      I assume that if this makes it unique, then ebola probably doesn't share the trait.

      Immunizing wild waterfowl in southeast asia would probably require something like a genetically modified bacteria that expressed the same antigens as the virus, triggering immunity. Such a bacterium could be introduced into their habitat.

      However, since pigs are the intermediary link, it would probably be much easier to innoculate pigs at the same time you innoculate humans. Then you could use a normal vaccine. But first you have to make a vaccine that targets some highly preserved section of the viral DNA, since the protein coat mutates quickly.

      • And if this became the method of choice, Department of Agriculture vets could vaccinate the piggies as they're doing other vaccinations, to ensure that it's covered properly, rather than counting on thousands of small town and rural vets to do it. The government could get involved! Billions of dollars could be spent! Seriously, they haven't figured out how to stop West Nile yet, I don't think the flu is at the top of the priority list. But isn't it a wonderful thought that just by giving a bunch of piggies shots in the butt, you'd never have to suffer from the flu again?

        At least until some Chinese chicken escaped and wreaked havoc with our now-unsuspecting immune systems?

  • This is amazing. Most of the problems that we have with influenza A is that it has a high rate of mutation that allows it to be essentially a different virus every time it whips around the globe. However, a site like that that is crucial for the virus' reproductive cycle would be highly conserved. If we could design/discover drugs that would target that RNA interaction we could really put a damper on Influenza's infection rate. I went looking at PNAS and I couldn't find the paper, so I'm not sure what his experimental procedure was.

  • One thing that always worries me (Score:3, Insightful)

    by phorm ( 591458 ) on Thursday January 30, 2003 @05:43PM (#5191520) Journal
    When scientists are attempting cures with diseases at a genetic level, there is always a possibility of creating something worse, or a really nasty mutation. Antibiotics, for example, can make a virus more resistant if they don't kill it the first time around.

    Still, I am hopeful - since the more we know about such virii, the better we can combat them. The issue is in knowing enough to develop countermeasures but not enough to predict future consequences.

    • Re:One thing that always worries me (Score:4, Interesting)

      by Simon Field ( 563434 ) on Thursday January 30, 2003 @08:24PM (#5192713) Homepage


      Of course, antibiotics aren't useful against viruses, but presumably any antiviral agent that does not kill the virus effectively will give the virus a better chance at developing resistance.

      I am somewhat skeptical (ok, paranoid) about the motives of drug companies. It looks to me like it is in their best interest to develop drugs that turn a fatal disease into a chronic one that needs expensive drugs for life. If they develop drugs that actually cure the disease, they make less money. Where is the most money being spent and made -- on anti-virals, or on vaccines?

      How many companies that sell cold remedies are working on vaccines for the common cold?

      • It would be a waste of time to work on a vaccine against the common cold. Vaccines are typically designed to target an immune response based on coat proteins (the antigen) displayed on the exterior of a microorganism.

        Unfortunately, the high mutation rate of many microorganisms causes these coat proteins to dramatically change between successive generations, which would make a vaccine against one generation of a bug ineffective against another generation.

    • Its important to point out that antibiotics cannot and do not make bacteria resistant. Due to the immense populations that bacteria like to exist in, toss in some regular Mk1 Mod0 life randomness, there is almost a certainty that a percentage of the bacteria that already exist in a population are already resistant to the antibiotic before you even apply it. So, all you do is chop off the part of the population distribution that is susceptible to the antibiotic and the resistant ones get to grow and multiply to fill the space once occupied by antibiotic-susceptible bacteria. I am so sick of so-called medical experts screwing this up in print and TV news. Its one thing to wallow in your own ignorance, its another entirely to pass your disease onto others!

      Just a further note though, very few antibiotics actually work on bacteria at a DNA level. Most instead like to hack and slash at a bacteria's cell wall or plasma membrane. Some (my personal favorites) are metabolism arresters that attack metabolic enzymes that the bacteria uses to make energy for life processes.

      • I've been told several times (by people ranging from home-remedy moms to doctors/nurses etc) that if you take antibiotics or other related pills, but only take say 50% of them... and don't really kill off the disease, then said medication becomes much less effective in containing said disease when symptoms reoccur.
        This is not true?
        • Yes it is generally true, but why?

          If there are lots of germs/bacteria that are giving your child a sore throat, the total population will be affected by a prescribed antibiotic to varying degrees, almost none being totally resistant - and the immune system can take care of a certain quantity of the bacteria whatever its reaction to the antibiotic.

          In few cases that I can think of does a medication work with only one dose. Almost ALL antibiotic treatment regimens are for a period of time because some of the bacteria can withstand 4-5 days of antibiotic exposure, but are killed with 7-10 days of treatment. In addition, the presence of the antibiotic can interfere with the life cycle of the bacteria, allowing the immune system more time to be effective.

          Your child, for whatever reason, has a sudden increase in the number of bacteria and exhibits a sore throat. You take him/her to the doctor and get a prescription for an antibiotic. You give the first several dosed, and those bacteria most susceptible to the antibiotic are killed, as well as the immune system doing its best to deal with the infecting agent. Because of the decrease in number of bacteria, there are no more symptoms, so you stop giving the antibiotic to your child.

          The bacteria that are left, even if brought back to "normal flora" levels by the immune system, are the ones that were not killed by the levels of antibiotic in the system achieved and sustained in the aborted treatment cycle - i.e., they 'resisted' the antibiotic. Therefore, if the symptoms return, it may well be because the 'resistant' bacteria have increased in number and are much tougher to eradicate with the same antibiotic the second time - the sore throat does not respond as before, because all the susceptible bacteria were killed the first time, and these are descendents of the 'resistant' germs.

          • So basically what you're saying is that:
            The bacteria more succeptible to the antibiotic are killed in the initial stages of treatment, but unless you continue nuking them for awhile then it's the remaining antibiotic-resistant strains that begin propogating again.

            So, they don't truly spawn antibiotic resistant mutations, just propogate from the existant resistant strain.

            This makes sense, and is a little less scary than having them "mutate" to adapt... but still leaves us with more resistant virii in the future :-(
  • I have a puzzling question (for me at least, with no experience working with diseases, bacteria, etc). If we were to isolate every single person infected with influenza, or HIV, or any other virus that can not live outside of the human body long, and keep their bodily wastes (feces, urine, moisture from their breath, etc) away from everybody else, would these diseases disappear forever? Very unfeasible, I know, but humor me if you will...
    • Probably not. I'm not a virologist but it wouldn't necessarily be enough to eradicate the disease among humans only. Some (many?) virii have the ability to infect multiple species, for example the West Nile virus can infect humans, horses, and crows. Also I remember years ago when I was an undergrad looking at a cladogram following the evolutionary phylogeny of the AIDS virus. At that time there were only a couple hundred different virii but they targeted more than one species. Virii mutate, so its possible under odd circumstances that they occasionally jump species, so a related influenza, AIDS, etc. could reinfect us. Little bastards.
    • Well, smallpox was eradicated by immunizing everyone. There have not been any natural cases of smallpox for a long time, and there will be none unless some madman commits a crime against all of humanity by re-releasing that virus.

      However, influenza, for example, infects other animals than humans. So does the bubonic plague. Complete eradication of these disease would therefore be very difficult.

      Polio can be eradicated, though, and so could some others, because no other hosts than humans exist. We are well on the way to eradicating polio.
      • We are well on the way to eradicating polio.

        Shit, they make such great shirts.
      • Actually, no.

        Influenza, much like the common cold, just has a high-mutation rate.

        Smallpox was a single species of virus. Influenza is not. Influenza changes and adapts every year.

        You remember how if you get chickenpox once, you never get it again? Smallpox is the same. Once a virus is terminated within your system, it has no chance to resurface on the basis that you have antibodies with which to defeat it.

        How many flu shots have you had in your life? I personally have had about 10... Which would seem pretty silly to have it done needlessly. If I'd already had my shot, it should be done with, and I shouldn't need any more. But the fact of the matter is that every year new influenza viruses come out which is why, theoretically, we should be getting flu shots every year.
    • One problem (among many others) is that frequently by the time you know you have a disease, you've already passed it on.


      • This is one of the arguments for vaccinating children early.

        If we have good vaccines for the people who can afford them, the free enterprise system detects success, and stops looking further. To actually eliminate a disease, such as smallpox or polio, governments (or other non-profits) must come in and make sure that those who can't afford it are also immunized.

        Would cold-remedy manufacturers lobby against eradicating the common cold?

    • Yes, this is correct. Virulent microorganisms (those that infect humans) require a suitable host in order to survive and propogate. Without one, they would soon perish.

  • Influenza pandemics (Score:2, Interesting)

    by juushin ( 632556 )
    The article is interesting, but falls a bit short of describing why this study describing how viruses package themselves and spread is so important (it does briefly mention the influenza pandemic of 1918 which is believed to have killed tens of millions worldwide, thereby illustrating the devastation of influenza).

    What the article fails to mention is how strains of influenza can become particularly virulent against humans. Traditionally, as in the 1918 pandemic, this occurs when a strain of swine and avian influenza combine. The likelyhood of this recombination occurring to produce a lethal strain is low (consider that the Spanish Influenza was brought about by a strain of avian influenza believed to originate in China and a swine strain believed to have originated from another area of the world). However, statistics show that this recombination occurs regularly enough to pose a serious risk and that it is only a matter of time...

    If one traces outbreaks of influenza worldwide, it becomes clear that every ~20 years, an outbreak occurs due to a recombination of swine and avian viruses that leads to the infection of humans.

    Let's hope that scientific strides, such as that made in this recent PNAS article, can be used to nip future viruses in the bud, or be used to make new vaccines.

    I had a little bird It's name was enza

    I opened the window

    And in-flu-enza

  • If anyone needs a sample of the influenza virus, please contact me. It is running rampant through my system.

    Research inquiries only.

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