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Biotech

Study: Certain Vaccines Could Make Diseases More Deadly 195

sciencehabit writes: New research suggests that vaccines that don't make their hosts totally immune to a disease and incapable of spreading it to others might have a serious downside. According to a controversial study by Professor Andrew Read these so-called "imperfect" or "leaky" vaccines could sometimes teach pathogens to become more dangerous. Sciencemag reports: "The study is controversial. It was done in chickens, and some scientists say it has little relevance for human vaccination; they worry it will reinforce doubts about the merits or safety of vaccines. It shouldn't, says lead author Andrew Read, a biologist at Pennsylvania State University, University Park: The study provides no support whatsoever for the antivaccine movement. But it does suggest that some vaccines may have to be monitored more closely, he argues, or supported with extra measures to prevent unintended consequences."
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Study: Certain Vaccines Could Make Diseases More Deadly

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  • by Etherwalk ( 681268 ) on Monday July 27, 2015 @06:00PM (#50193729)

    The idea is that if you vaccinate people but they still get the disease and don't get it as badly, they might not die as quickly, or might not die.

    So if they get sick but don't die, the disease has longer to spread.

    So I suppose if you're an Anti-vaxxer it's a great argument for why only you should get vaccinated for highly virulent diseases, but you should just let everyone else die faster.

    • by tnk1 ( 899206 ) on Monday July 27, 2015 @06:14PM (#50193825)

      It's a good argument for ensuring you don't have half-assed vaccines, which is a legitimate concern.

      It's the same problem as those people who are prescribed antibiotics and don't finish their full course: that's how you get antibiotic resistant bacteria. You half-assed the treatment, now the surviving bacteria are the individuals with adaptations that were best able to resist the antibiotic. Usually, the disease would progress where the antibiotic vulnerable bacteria would compete. With the help of the incompletely used antibiotic, there's now only resistant bacteria left to infect a new host.

      This is not an anti-vaxxer argument, as those fools think that the vaccine causes problems unrelated to what it is supposed to be preventing (like autism), rather than this case being that the vaccine was simply too weaksauce to do the job right, so it made the problem worse by selecting out the bacteria more likely to succumb to the vaccine-adjusted immune system.

      • by rioki ( 1328185 )

        I hate it every time some research comes out that tries to shines some light at shortfalls in current research and then it is "controversial" because it "could give an argument to the anti-XYZ". This comes up with vaccine research, climate research and whatnot. I think every person that utters something like that is actually undermining the entire legitimate research community. The forced need to appear to be united give the opponents more suspicion, not less.

      • It's still a moron argument. Any argument that goes by the "if he only died faster none of this would have happened" is a bad argument. Corpses can also spread disease as well FWIW.

        • by arth1 ( 260657 )

          Corpses can also spread disease as well FWIW.

          Only if you keep them around. Which is chiefly a religious and cultural choice, not a scientific one.

      • No, it's not the same problem at all. *No* vaccine is perfect, whether it's because the pathogen mutates slightly, or because the immune system doesn't learn that the (harmless) pathogen in the vaccine was harmful. The way vaccines work isn't perfect immunity, but herd immunity. They work well enough to prevent outbreaks, which is a public health concern, and if you're one of the lucky ones for whom the vaccine worked, then you're better off too. Unfortunately, there's no way to know, beforehand, whethe

    • by mjwx ( 966435 ) on Monday July 27, 2015 @08:07PM (#50194359)

      The idea is that if you vaccinate people but they still get the disease and don't get it as badly, they might not die as quickly, or might not die.

      However this is not how vaccines work. I suspect the fine article got a lot wrong.

      The idea is that if you vaccinate people they have an increased immunity to the pathogen and have a greater chance of not becoming infected if exposed. This slows or stops the spread of the pathogen amongst a community.

      • Sometimes you only get 'partial immunity'.. like wise you can have some benefit to being administered a vaccine after infection. You'll still get sick, but it won't be as severe. For human medicine this is fine, for livestock having a bunch of sick animals may be as bad as having a bunch of dead ones.
  • by Opportunist ( 166417 ) on Monday July 27, 2015 @06:08PM (#50193787)

    Pathogens don't "learn". They evolve, ok. They adapt, ok. But they aren't sentient. They are not thinking. And especially they aren't thinking "hey, if they vaccinate, they won't die anyway, at least not as fast, so let's get more deadly!" This isn't the fucking Pandemic flash game for crying out loud!

    There is no interest of killing a host for a parasite. It's an side effect. Unintended, and actually harmful for the parasite in the long run. Just like poisoning the seas is harmful for us. We ain't some comic book villain who does it for ... well, for being evil. We do it 'cause it cuts costs. The oil spill is only the side effect, not the reason we do it.

    So yes, they COULD get more deadly because we don't die as fast and a more deadly mutated strain would kill itself off with the host if there was no vaccination. But that is hardly an argument against vaccination. It only means that at worst we're with vaccination where we are now without. AT WORST. If, and only if, the pathogens mutate in such a way that they get more deadly. Which is neither in their interest nor anything they would (evolutionary) strive for.

    What's the benefit for a pathogen to be more deadly? Killing the host is actually bad for it, since that ends spreading (with this host at least).

    • by sjames ( 1099 )

      Machines are said to learn, but are not sentient and do not think. Memory plastic isn't sentient either.

    • by ITRambo ( 1467509 ) on Monday July 27, 2015 @06:28PM (#50193919)
      I don't think the strains that survive an incomplete round of antibiotics have mutated. They are simply the strongest ones that are now given a chance to multiply, since someone didn't take their complete prescription. These stronger bacteria can now be exposed to more antibiotics and the strongest again survive and reproduce. Soon we have antibiotic resistant bacteria strains that otherwise would have been a tiny percentage of the population. They haven't "learned" anything. It's survival of the fittest only.
      • by Obfuscant ( 592200 ) on Monday July 27, 2015 @07:24PM (#50194173)

        I don't think the strains that survive an incomplete round of antibiotics have mutated.

        You then proceed to describe exactly the process through which the antibiotic sensitive bacteria die so the mutations that have resistance become dominant. Where do you think those antibiotic resistant bacteria got their immunity to that specific antibiotic? They didn't order it from Amazon Prime, just sayin.

        It's survival of the fittest only.

        And those "fittest" become so because ...?

        • by tsa ( 15680 )

          That's the wrong interpretation of "fittest." I don't know who coined the phrase (it certainly wasn't Darwin) but in the context of evolution "fittest" means the individual organism that is best suited to the environment it lives in, which is not necessarily the strongest individual.

          • by tomhath ( 637240 )

            That's the wrong interpretation of "fittest."

            That's exactly the definition of "fittest". Able to survive in the environment (in this case exposed to an antibiotic) better than others of the same species. Whether you use the word "fittest" or "strongest" is irrelevant.

        • Comment removed based on user account deletion
      • by Reziac ( 43301 ) *

        Not materially different from your immune system killing off the weaker individuals. A few stronger individuals may survive, and then what has your immune system done? Selected for a stronger pathogen.

        I remember a paper from a few years ago which concluded that this was basically how we wound up with deadly diseases in the first place -- being the ones that throughout history have managed to be stronger than the host's immune system.

        Vaccine simply cuts out the stage where lots and lots of hosts get sick or

    • by mjwx ( 966435 )

      What's the benefit for a pathogen to be more deadly? Killing the host is actually bad for it, since that ends spreading (with this host at least).

      Our assumptions about evolution is that its driven by the need to survive. When a pathogen is faced with a change in their environment bought on by a pharmaceutical treatment it is possible for a pathogen to adapt to fight or avoid that treatment. This does not mean they'll automatically adapt (they're not the Borg), in fact in most cases the opposite can occur

      • > evolution does not consider risks and benefits, changes are random

        Interestingly, not all changes are random. There are some fascinating changes in DNA triggered by environment, many of them studied as "epigenetics". And there are certainly changes in organisms that are defensive responses to environment. The darkening of skin under sunlight is a classic example. Evolution occurs at _many_ levels. These include environmental, biological, behavioral, cultural.

    • by fermion ( 181285 )
      Unfortunately even science people are afraid of using the word evolution because some religious whacko might want to shoot them. So other words are used like 'learned'.

      In fact the human vaccines to treat the most virulent viruses, the one's that don't kill quickly but rather maim, have worked well. Small pox is eradicated, and Polio has not been seen in Nigeria for a year. Some people get sick from Vaccines, but they likely would have the most susceptible and the carriers anyway.

      What is being seen is

    • by tomhath ( 637240 )
      The argument is that some of the organisms have a slightly higher resistance to the host's natural defense system. If the vaccine doesn't cause that system to kill all of the pathogens, the ones that survive are better able to infect other hosts. It's a very plausible theory.
  • I mean really, it's in the name of science [xkcd.com] right?
  • We have for a real-world counter example the (live) attenuated disease vaccines.
    Foe example, the live polio vaccine and we have the vaccinia vaccine. (anti-smallpox vaccine)
    Have either of those resulted in increasedly virulent strains of those diseases?
    I'm not 100% sure, but the eradicated disease that no one knows about, rinderpest, I believe, used an attenuated vaccine as well.

    • Where the Oral polio vaccine does sometimes cause polio, it hasn't yet caused a new more virulent strain of polio to appear. What they say is that sometimes the attenuated Polio virus mutates back into the non-attenuated version and can infect the recipient. The injectable version of the vaccine never causes Polio. This vaccine has been in nearly constant use since it came out in the late 60's, so I think that for Polio at least, the vaccine hasn't had this affect of creating a SUPER POLIO virus, but it

      • Re:a counter-example (Score:5, Informative)

        by clovis ( 4684 ) on Monday July 27, 2015 @11:24PM (#50194967)

        Yup to what you said.
        I truncated my earlier post because I got a call from downstairs that salad, baked chicken, yellow rice was on the table, and strawberries had been cut up for the home made ice cream in the freezer. I believe my priorities are in order.

        Reading the study makes it clear that what is happening with these chickens is important to the poultry industry, it's not just a what-if study, it's a "this has happened and we need to find out why" kind of thing.

        Anyway, for the benefit of readers who may not have time to read the actual study, in the study, the author mentions what we said, that the increased virulence example that he had discovered for this virus, Marek's virus, had not been seen in human hosts for human diseases.
        From the article:
        "The imperfect-vaccine hypothesis attracted controversy [11–14], not least because human vaccines have apparently not caused an increase in the virulence of their target pathogens"

        Furthermore, the author says:
        "Our data do not demonstrate that vaccination was responsible for the evolution of hyperpathogenic strains of MDV, and we may never know for sure why they evolved in the first place. Clearly, many potentially relevant ecological pressures on virulence have changed with the intensification of the poultry industry."

        The study also discusses similar phenomena that occurred naturally when exposed survivors in the wild harbored an increasedly virulent pathogen due to their acquired partial immunity after exposure.

        What I think is interesting is that the increased virulence of Marbek's is only found relative to unvaccinated chickens. The vaccinated chickens do not experience the increased virulence.
        If there is a lesson in this for human vaccines, it is that when we vaccinate, we need to vaccinate as much of the population as is possible, and that you really do not want to be the unvaccinated ones if an analogue does appear in the human population.

        Anyway, this actual study is interesting, and I don't see any problems with the way it was executed or written. As is so often the case, the problem comes from people extrapolating from a study things that are not found in the study.

  • by liquid_schwartz ( 530085 ) on Monday July 27, 2015 @06:53PM (#50194039)

    ...they worry it will reinforce doubts about the merits or safety of vaccines...

    This attitude about let's not discuss any possible downside because it will give the anti-vax people ammunition is part of the problem. Often forgotten is that a certain percentage of people who get vaccines die. That's an extreme form of take one for the team. At least some of these deaths could probably be prevented but rather than examine that more seriously we get polarized into vaccines are always good with no room for an opposing view. Any opposing views must be the opposite end of the spectrum and must be 100% against vaccines. While vaccines have been outstanding public policy in general that doesn't mean that it couldn't be improved upon. As long as people die from vaccinations there is room for improvement. The fact that we don't seem to be looking into how to lower that number is a problem.

    • by Sowelu ( 713889 )

      I'd say that people who insist that evil scientists are refusing lower that mortality rate are a much bigger part of the problem. Um, that research is still happening. The fact that you haven't heard of breakthroughs recently can just as easily mean that 1) nobody bothered to write about it or 2) it's a really hard problem, despite the large amount of money thrown at it.

      Also, maybe it sucks, but if you have limited research resources, it's more efficient to try and develop a new vaccine to save millions o

      • Also, maybe it sucks, but if you have limited research resources, it's more efficient to try and develop a new vaccine to save millions of lives than it is to improve an old one and save dozens.

        Or you could just spend more money on your PR and advertising. Like Merck did with the MMR. The Mumps part of the vaccine has been sold to us as being 95% effective. Well it seems they have been lying to the government and the population for a few decades now and it is much closer to 35% effective. Why spend money unwisely when you can control what people believe so easily. And anyone who doubts the effectiveness of a vaccine is labeled an "anti-vaxxer" who should be shot on sight. Yeah, the pro-vaxxers are

    • by phantomfive ( 622387 ) on Monday July 27, 2015 @07:28PM (#50194197) Journal

      The fact that we don't seem to be looking into how to lower that number is a problem.

      The problem is you don't spend 15 seconds on Google before spouting off. A quick search would have found you this page: Goal 1: Develop New and Improved Vaccines [hhs.gov]. The national vaccine plan says, "Research to improve existing vaccines also provides opportunities to improve on a range of vaccine characteristics such as efficacy, safety, and vaccine delivery."

      As a bonus to you, the page lists these recent advances in vaccine technology:

      * Advances in scientific understanding of diseases and vaccine responses, especially for pertussis, pneumococcal disease, dengue and hepatitis C.
      * New vaccine production techniques and technologies.

      Research a little and your posts will be more coherent; your brain will be clearer.

    • by tsa ( 15680 )

      You should first find out what the people died of. The people who "die from a vaccine" often die from something completely unrelated to the vaccine. If you calculate the number of people who really die because of the vaccine it might be such a small percentage that it's not worth the effort to improve the vaccine.

      • by delt0r ( 999393 )
        The most common improvement is to bundle vaccines together. Since the leading cause of unvaccination? is in fact the dozen or so doctors visits in many places. In fact that is also one of the leading costs. Combining 3 into 1 is pretty close to 3 times cheaper.
    • This attitude about let's not discuss any possible downside because it will give the anti-vax people ammunition is part of the problem. Often forgotten is that a certain percentage of people who get vaccines die.

      Your claim has no source so I'll provide one [skepticalraptor.com]. Summary there is currently no evidence to support a causal relationship between vaccinations and death. So there is no evidence that vaccines are causing the death of anybody at all. Zero deaths given the huge power of the study (13 million people and 24 million vaccinations).

  • by tobiah ( 308208 ) on Tuesday July 28, 2015 @12:27AM (#50195071)

    I'm impressed that slashdot can push out this clickbait Monday evening, and that less than 64 people dispute that vaccines suck (excepting those who responded: trolls.)

  • The title of the paper is "Imperfect Vaccination Can Enhance the Transmission of Highly Virulent Pathogens". Note the absence of any question marks or qualifiers such as "could...?"

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