Evolution of disease - Page 2

[MissRubyandKen]

gr8blessings-

I wanted to say that I 'get' what you are saying. I'm in no way denying that vaccine derived polio virus can be transmitted to unvaccinated people and circulate, mutating over time. And I understand the veiwpoint that interruption of transmission of wild type polio and the cessation of OPV use may eventually stop this. I 'get' the goal. I just disagree the effort should have ever been made and believe whole heartedly there was and is a better way to go about reducing any harm this virus can cause without harming children in the process.

[Deborah]

Originally Posted by MissRubyandKen

gr8blessings-

I wanted to say that I 'get' what you are saying. I'm in no way denying that vaccine derived polio virus can be transmitted to unvaccinated people and circulate, mutating over time. And I understand the veiwpoint that interruption of transmission of wild type polio and the cessation of OPV use may eventually stop this. I 'get' the goal. I just disagree the effort should have ever been made and believe whole heartedly there was and is a better way to go about reducing any harm this virus can cause without harming children in the process.

Most people who got polio never got noticeably ill. A few people got mildly ill. A very tiny percentage became seriously ill. But except for a few weird alternative doctors, no one ever tried to figure out why polio only got serious in a small group. The assumption was that it was completely random, totally unpredictable, nothing to be done except create a vaccine and give it to everyone.

Once you start down that road you end up with the current situation.

Has anyone heard of acute flaccid paralysis? Sometimes caused by polio but it can be caused by other stuff. Another opportunity to find out why only a few people out of many exposed to a risk factor become sick.

[zylph]

Originally Posted by MissRubyandKen

Mutations can occur in either vaccinated or unvaccinated individuals. I don't agree that overall bacterial or viral load is going to be lower in a vaccinated individual. Possibly for the specific bacteria if transmission has been interrupted and carriage has been lowered, yet other bacteria will fill this void, won't they? Numerous studies have been done that show carriage of one bacteria affects another, and as one has went down another has went up.

I'd like to come back to the flu discussion. From my reading it makes little sense that mutations would be more likely to occur in unvaccinated people. What % are we talking about here? How much more likely do you theorize this is to happen? The flu is constantly mutating, it is the nature of the beast. Even if 100% of the population had a flu vaccine, this would still occur, wouldn't it? Can we foster hostility towards those who abstain from vaccines over this?

In any one person who winds up getting infected even though they've been immunized (due to failure to seroconvert or whatever), the viral load may be just as high. But if you take 50 people who have been immunized against measles and 50 people who have not and expose them all to measles, I guarantee you that there will be many orders of magnitude difference in viral load between the two groups. This is important, because every time the virus replicates, it has a chance to mutate its antigens into a form different from the vaccination strain.

(Bacteria do fill certain niches in the body - the good, or commensal, bacteria that normally live in your gut are killed off by antibiotic treatment, opening up an ecological niche for more pathogenic bacteria. Which is why diarrhea is a common side effect of antibiotics. But the bacteria we immunize against don't normally fill any ecological niche in the body)

As far as the flu, mutations are not any more likely to occur in immunized vs unimmunized people. Productive infection is more likely to occur in unimmunized people, and the increased replication allows more mutation to occur. And yes, 100% immunization against flu would not prevent the flu from coming back the very next year. Because there are billions of pigs and birds out there that serve as the unimmunized population. This is not about demonizing anybody. It is not yours (or anybody else's) responsibility to keep the purity of the vaccine strain intact if you don't think the benefits of vaccination are worth the risk. But having a large unimmunized population does reduce the effectiveness of vaccines.

[ccohenou]

Originally Posted by kiara7

It doesn't make any sense if one thinks about it. Current strains have no reason to mutate in an unvaccinated individual.

Mutation is random. There does not need to be any reason for it to occur beyond a random error in replication or reverse transcription or whatever genetic process the virus might carry out. Some mutations are more successful than others, sometimes because they (randomly) happen to get around some aspect of immune defense (vaccinated or un).

More infections means more production of many many copies of virus which means more opportunity for mutation. It's just like throwing dice - more throws - more snake eyes.

ETA looks like I am maybe echoing zylph.

[medusaatemydog]

Originally Posted by zylph

It is not yours (or anybody else's) responsibility to keep the purity of the vaccine strain intact if you don't think the benefits of vaccination are worth the risk. But having a large unimmunized population does reduce the effectiveness of vaccines.

A large immunized population does reduce the effectiveness of a populations' natural immune response (making room for far more dangerous and viral strains, resulting in a never-ending call for more vaccines and more damage)and does cause neurological and major bodily organ damage....

The problem is we are human and made of biological cells that have been adapting to 'natural' disease since ... we evolved... for some reason there are people who think that the human immune system is no longer valid and we must correct it with a synthetic one or a more profitable one...

It is quite clear ...as big as king kong... that vaccines cause serious health problems... whether or not a person feels the need to exchange chronic dysfunction and a synthetic tempory immunity is worth it for that person and their prodgeny , well that is fine for that person ... but i do not want to make the trade, i feel the price is too high in the long run..
it's alright to say vaccinosis is real in animals but it's when it comes to people... it's just not profitable enough... one should watch the stock market dance whilst this drama of this mild flu dances around the world.. people in mexico die from a flu because they are extremely poor and live in very bad conditions... getting to a clinic ..if they can get there...is one thing... most of the time they don't have the money to get there or pay for the meds, not to mention thier nutrition and health status is really poor

[medusaatemydog]

i have a picture of the future generation of whom don't live long because thier immune systems can no longer carry them through a normal life span... carry around a box of syringes... and they are full of thier daily vaccines... the never-ending prick... what pharmacutical company owns your immune system??? The idea that everything will be solved with a vaccine is seriously corrupt..

[kiara7]

Originally Posted by zylph

But having a large unimmunized population does reduce the effectiveness of vaccines.

How does my unimmunized existence reduce the effectiveness of vaccines exactly?

[MissRubyandKen]

Originally Posted by zylph

...But the bacteria we immunize against don't normally fill any ecological niche in the body...

...Because there are billions of pigs and birds out there that serve as the unimmunized population...

...But having a large unimmunized population does reduce the effectiveness of vaccines.

Prevaccine Hib could be found asymptomatically in some percent of normal children and adults too. Nearly all children had immunity by age 5-6 by asymptomatic infection. Only a small percent of children suffered from invasive disease. Now that carriage of Hib has been lowered rates of invasive disease of other Hi has increased, has it not? Didn't we trade one disease for another? Pnuemococi are normal inhabitants of the respiratory tract. Again often asyptomatically with disease most often happening with a predisposing condition. Reducing carriage of the vaccine strains has saw an increase in non vaccine strains. Strept pneumoniae carriage, specifically of vaccine-type strains, is negatively associated with staph carriage in children according to this study. Meaning children who were carriers of s. pneumoniae were less likely to be carrying staph. These are examples of what I was referring to.There is serotype replacement and disease replacement taking place, correct? I know I'm talking about two different things here, so sorry if I'm being confusing.

The flu would mutate in a population with a 100% vaccination rate even if there were no animal carriers, I believe.

Having a large immunized population increases the likelihood of immunity waning by childbearing years. Also reduces a mother's ability to pass on protective antibodies to her baby. Our most vulnerable population left more vulnerable. Of course this seems offset by the large immunized population for the diseases with live vaccines, but would mean little in the event of an outbreak on the individual's level.

[LindsayK]

Thanks for all the responses!

So is the take-home here that, yes, disease can mutate into non-vaccine "protected" strains, but this can also happen within the vaccinated population, too?

Talking about this idea within the context of the flu makes a lot of sense, too, given that there is a lot of drift from year to year. This clearly isn't caused by the unvaccinated (alone, at least) and would continue to happen even if you had 100% vaccination coverage.

[MissRubyandKen]

Sorry OP for going off topic. It just seems that if someone wants to discuss possible negative impacts of not vaccinating they should also be willing to look at the possible negative impacts of vaccinating.

[MissRubyandKen]

I'm going to try to explain what I feel the relevance of the impact of vaccines is to the evolution of disease. I don't have college courses in the matter, nor do I have numerous years of practice at a relevant profession or have my hands in petri dishes of bacteria all day. So I might just be too ignorant to know enough relevant information to understand these issues. I hope someone will come along and tell me my concerns are unfounded, that I'm missing x information and haven't taken y into consideration. I've been trying to think of an intelligible way to explain this for days, because I'm just not all that good at explaining what I mean sometimes. So, I'm going to use a metaphor and hope that someone more educated will come along and point out all the flaws.

Suppose there is a town with an overpopulation of stray cats (pnuemococci). They are bothersome for many reasons, they spray, fight loadly, and occaisionally scratch, which can in rare circumstances lead to sickness. So we put out poison (antibiotics). This has an effect of killing some of the cats and also some mice (staph) too. But there are still too many cats being bothersome. So we go about slaughtering as many of them as we can (this would be the introduction of the pnuemococcal vaccine). Then the mice population (staph) goes up. They've already shown some resistance to the poison we've put out, it just isn't having enough effect on them. So we put out a different poison. Because their numbers have increased this gives them a greater chance at microevolving resistance to our poisons. And the mice actually become more bothersome than the cats ever were. Not only that but the increased mice population carries fleas which leads to bubonic plague. My point in saying this is the human ecology is a complex thing. We don't undestand all of the relationships of the numerous bacteria we carry and encounter. There are ways they can keep each other from becoming overpopulated within us. We don't know if there is a more dangerous, more deadly bacteria that could evolve to gain a foothold where before it couldn't due to lack of opportunity. Vaccines are an environmental pressure on bacteria. We don't know what effect this will have on our ecology in the future. We didn't forsee what the use of mass antibitotics would have. And while I do understand the effect was more direct, whereas vaccines are indirect, we can't act like it is no effect.