Evolution of disease

[LindsayK]

I was browsing through the reader comments of a pro-vaccine article on line the other day. One comment that made me think was a person who claimed that unvaccinated people serve as a repository of disease where the disease can mutate in the unvaccinated to become strains which aren't covered by vaccines. This would then endanger the vaccinated population, because the strains covered in the vaccine would no longer match the strains in the wild.

Is this true? Is there something that is missing in the argument?

[kiara7]

It doesn't make any sense if one thinks about it. Current strains have no reason to mutate in an unvaccinated individual. There is a normal immune response and normal antibodies are created.

In a vaccinated individual, however, there are already abnormal (or unnatural) antibodies in place (sometimes), thus a disease strain needs to mutate in order to survive. Think antibiotic resistant bacteria (MRSA), flu virus resistant to Tamiflu, serotype replacement, etc.

That pro-vax argument doesn't stand up to any scrutiny.

[Marnica]

That is ridiculous. As Kiara said, it makes no sense. Ask this commenter to post sources. Bet he/she can't

[MissRubyandKen]

A repository of disease? Really, lol. I have to laugh that they chose that wording to make their statement. I think they were likely meaning to parrot the phrase 'reservoir for disease'.

[MissRubyandKen]

Maybe you can ask them what they think about the viruses from the Oral Polio Vaccine mutating in vaccinated individuals.

Ask them if they know which vaccines can prevent transmission when proper immunity is gained and which don't.

Ask them if they have read anything about influenza mutations. It's laughable that an unvaccinated individual would be targeted as most likely to host a mutation, because of both the nature of the virus and vaccine.

[fresh_veggie]

: People are dorks. And people believe other dorks. And then people who actually do the research are blamed for everything. Why does it always work like this!?

That's totally not true. The diseases have no reason to mutate in someone who doesn't have the vaccine. The disease is a LOT more likely to mutate in someone who has had the vaccine. As we're now seeing.

I've had MRSA. In the hospital for two weeks because somehow my lady bits got ... yeah, ouch, to say the least. Because people have treated staph so unnecessarily with antibiotics, it's mutated in the TREATED ones.

Check it out though - my mom NEVER gave me antibiotics for anything. But I still picked up MRSA somewhere because other people have used so much antibiotics. (Or maybe it was because they fed me so much cheap meat and milk growing up. Anyway. OT rant there, lol.

[gr8blessings]

Yes, the blog commentator is correct. Here is a reference:

http://www.scielosp.org/scielo.php?s...rm=iso&tlng=en

gr8blessings

[Gitti]

Originally Posted by LindsayK

.. unvaccinated people serve as a repository of disease where the disease can mutate in the unvaccinated to become strains which aren't covered by vaccines.

Unvaccinated people do not serve as some sort of repository unless they came in contact with the virus/bacteria. Vaccinated people can also be carriers.

..the strains covered in the vaccine would no longer match the strains in the wild.

This also happens in the vaccinated. Viruses mutate. They want to live and they know how.

[Deborah]

from the link offered by Gr8blessings:

Within the past 4 years, poliomyelitis outbreaks associated with circulating vaccine-derived polioviruses (cVDPVs) have occurred in Hispaniola (2000–01), the Philippines (2001), and Madagascar (2001–02). Retrospective studies have also detected the circulation of endemic cVDPV in Egypt (1988–93) and the likely localized spread of oral poliovirus vaccine (OPV)-derived virus in Belarus (1965–66).

So it isn't that the diseases are evolving within just the unvaxed kids. In the case in question, the vaccine is spreading a version of polio, which is interacting with, supposedly, the wild polio and the two are combining to cause additional problems beyond what would, apparently, occur from just the OPV being spread around or just the wild polio being spread around.

Sounds fairly speculative. I wouldn't call that hard science.

[MissRubyandKen]

Originally Posted by gr8blessings

Yes, the blog commentator is correct. Here is a reference:

http://www.scielosp.org/scielo.php?s...rm=iso&tlng=en

gr8blessings

Show me a source that specifies a mutation of an OPV strain virus occurring in an individual who hasn't been vaccinated with the OPV. How can you blame someone who has abstained from the OPV for a mutated strain? Every outbreak I've read of where a mutation has occured started from an OPV strain mutating, with a vaccinated individual. Sure this would leave the unvaccinated susceptible to the strain, but if the OPV doesn't cover that strain adequately the vaccinated individuals are just as suceptible, and therefore likely to spread it. If it does cover it adequately why would a vaccinated individual need to worry about contracting it from the unvaccinated? Ah maybe because of the possibility of vaccine failure? But the OPV is very effective isn't it? What this situation is really about is a group of people deciding for the rest of the world to make extreme efforts to eradicate a disease called polio. No matter how many children they hurt in the process, it is worth it. Why should anyone have the free choice to abstain from a vaccine which may cripple their child when it hampers the goal of eradication? Naughty, uneducated foreigners who think they're being purposefully poisoned. And on top of it all let's blame the unvaccinated for the vaccine strain mutations too.

[gr8blessings]

Originally Posted by MissRubyandKen

Show me a source that specifies a mutation of an OPV strain virus occurring in an individual who hasn't been vaccinated with the OPV. How can you blame someone who has abstained from the OPV for a mutated strain? Every outbreak I've read of where a mutation has occured started from an OPV strain mutating, with a vaccinated individual. Sure this would leave the unvaccinated susceptible to the strain, but if the OPV doesn't cover that strain adequately the vaccinated individuals are just as suceptible, and therefore likely to spread it. If it does cover it adequately why would a vaccinated individual need to worry about contracting it from the unvaccinated? Ah maybe because of the possibility of vaccine failure? But the OPV is very effective isn't it? What this situation is really about is a group of people deciding for the rest of the world to make extreme efforts to eradicate a disease called polio. No matter how many children they hurt in the process, it is worth it. Why should anyone have the free choice to abstain from a vaccine which may cripple their child when it hampers the goal of eradication? Naughty, uneducated foreigners who think they're being purposefully poisoned. And on top of it all let's blame the unvaccinated for the vaccine strain mutations too.

From the outbreak in the DR and Haiti - Science Vol. 296. no. 5566, pp. 356 - 359

Only one patient had a record of receiving three doses of OPV.

from http://www.cdc.gov/mmwr/preview/mmwrhtml/mm4948a4.htm:

The differences in nucleotide sequences among the outbreak isolates suggest that the virus has been circulating for approximately 2 years in an area where vaccination coverage is very low and that the virus had accumulated genetic changes that restored the essential properties of wild poliovirus.

So the virus comes from a vaccinated person, replicates and mutates into a more virulent form amongst the unvaccinated for 2 years and then infects a vaccinated person. So yes, the unvaccinated became a reservoir that infected a vaccinated person. Currently, the vaccine matches these mutated strains and vaccination has stopped these outbreaks. These outbreaks have occurred when vaccination rates drop below levels to maintain herd immunity. So in other words, if there were not unvaccinated persons within the community, these mutated strains would not emerge and infect others. The vaccine is very effective at preventing infection so obviously most of the persons infected are unvaccinated or partially vaccinated, but the fact that one completely vaccinated person was infected is enough to refute the argument that non-vaxers are not a source of infection for the vaccinated. How long would it be before enough mutations occur so that the vaccine is no longer effective? How many persons will suffer from polio until the vaccine can be re-formulated to match the mutated strain?

As for the decision to eradicate polio: The harm done from the disease is FAR greater than either IPV or OPV. I would like to see a reference that supports your claim that the vaccines cause MORE harm than the wild virus (i.e. why we would be better off if we never vaccinated for polio in the first place). Once wild virus is eliminated then vaccination programs switch to IPV, which will maintain immunity and not cause vaccine strains to enter an environmental reservoir. Once the environmental and human reservoirs are eliminated, it is quite possible, although not an easy task, that we can eradicate polio from the face of the earth, just like we did with smallpox. Nevertheless, this decision has already been made and OPV has introduced circulating vaccine-derived poliovirus (cVDPV). Not vaccinating is not going to change that. Not vaccinating will allow cVDPV to continue to infect and cause harm to others.

Some people choose to not vaccinate against polio because the wild virus is no longer present in their country. What these studies show is that mutated vaccine strains ARE present and replicating among non-vaccinated people. Infection with these strains are more likely to cause paralysis than the wild virus. Immunization prevents infections from these mutated strains as long as immunization rates remain high. Proper hygiene and other factors (see the WHO bulletin for more detail) also plays a role, but all it takes is one natural disaster (hurricane Katrina comes to mind) and all our sanitation infrastructure is gone.

gr8blessings

[MissRubyandKen]

Originally Posted by gr8blessings

From the outbreak in the DR and Haiti - Science Vol. 296. no. 5566, pp. 356 - 359


from http://www.cdc.gov/mmwr/preview/mmwrhtml/mm4948a4.htm:


..Once wild virus is eliminated then vaccination programs switch to IPV, which will maintain immunity and not cause vaccine strains to enter an environmental reservoir.

..I would like to see a reference that supports your claim that the vaccines cause MORE harm than the wild virus (i.e. why we would be better off if we never vaccinated for polio in the first place).

...if there were not unvaccinated persons within the community, these mutated strains would not emerge and infect others...

...the fact that one completely vaccinated person was infected is enough to refute the argument that non-vaxers are not a source of infection for the vaccinated...

..Nevertheless, this decision has already been made and OPV has introduced circulating vaccine-derived poliovirus (cVDPV).

gr8blessings

I snipped out what I'd like to respond to in the post. First off, that link doesn't work. Please fix it. Second, the Global Polio Eradication Initiative DOES NOT recommend countries switching to IPV after virus transmission has been interrupted. #10 This isn't in THE PLAN. Third, I never said the vaccine causes more harm than wild polio. I said the choice to start vaccinating globally in an attempt to eradicate polio was made for the world. Fourth - If there were not vaccinated persons within the community, these mutated strains would not emerge and infect others. These attenuated strains are mutating in the gut of the vaccinated individual. Fifth- The fact that one completely unvaccinated person was infected with a disease that mutated inside a vaccinated person is enough to the argue that vaccinated individuals are a source of infection for the unvaccinated. Who contracted the virus from whom?

Lastly I'll just reiterate your words 'Nevertheless, this decision has already been made and OPV has introduced circulating vaccine-derived poliovirus (cVDPV).'

Some links for you to read if you care to.

1
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6

[kiara7]

Originally Posted by gr8blessings

Infection with these strains are more likely to cause paralysis than the wild virus. Immunization prevents infections from these mutated strains as long as immunization rates remain high.
gr8blessings

How does vaccination with IPV/OPV protect against the new mutated strains?

[kiara7]

Originally Posted by gr8blessings

So the virus comes from a vaccinated person, replicates and mutates into a more virulent form amongst the unvaccinated for 2 years and then infects a vaccinated person. So yes, the unvaccinated became a reservoir that infected a vaccinated person.
gr8blessings

???

[MissRubyandKen]

gr8blessings-

The pneumococcal and Hib vaccines are having affects as far as selection and resistance, whether indirectly or not. Vaccines and antibiotics have had and are having quite an impact.

I really don't understand how you can morally blame disease evolution on unvaccinated individuals. Especially considering some mutations and selections have been specifically triggered by vaccines.

A mutation can occur in either an unvaccinated or vaccinated individual, or even an animal for some diseases that can cross species.

[MissRubyandKen]

Insidevaccines has some info. If you poke around you'll find more.

[runes]

Originally Posted by gr8blessings

From the outbreak in the DR and Haiti - Science Vol. 296. no. 5566, pp. 356 - 359


from http://www.cdc.gov/mmwr/preview/mmwrhtml/mm4948a4.htm:


So the virus comes from a vaccinated person, replicates and mutates into a more virulent form amongst the unvaccinated for 2 years and then infects a vaccinated person. So yes, the unvaccinated became a reservoir that infected a vaccinated person. Currently, the vaccine matches these mutated strains and vaccination has stopped these outbreaks. These outbreaks have occurred when vaccination rates drop below levels to maintain herd immunity. So in other words, if there were not unvaccinated persons within the community, these mutated strains would not emerge and infect others. The vaccine is very effective at preventing infection so obviously most of the persons infected are unvaccinated or partially vaccinated, but the fact that one completely vaccinated person was infected is enough to refute the argument that non-vaxers are not a source of infection for the vaccinated. How long would it be before enough mutations occur so that the vaccine is no longer effective? How many persons will suffer from polio until the vaccine can be re-formulated to match the mutated strain?

As for the decision to eradicate polio: The harm done from the disease is FAR greater than either IPV or OPV. I would like to see a reference that supports your claim that the vaccines cause MORE harm than the wild virus (i.e. why we would be better off if we never vaccinated for polio in the first place). Once wild virus is eliminated then vaccination programs switch to IPV, which will maintain immunity and not cause vaccine strains to enter an environmental reservoir. Once the environmental and human reservoirs are eliminated, it is quite possible, although not an easy task, that we can eradicate polio from the face of the earth, just like we did with smallpox. Nevertheless, this decision has already been made and OPV has introduced circulating vaccine-derived poliovirus (cVDPV). Not vaccinating is not going to change that. Not vaccinating will allow cVDPV to continue to infect and cause harm to others.

Some people choose to not vaccinate against polio because the wild virus is no longer present in their country. What these studies show is that mutated vaccine strains ARE present and replicating among non-vaccinated people. Infection with these strains are more likely to cause paralysis than the wild virus. Immunization prevents infections from these mutated strains as long as immunization rates remain high. Proper hygiene and other factors (see the WHO bulletin for more detail) also plays a role, but all it takes is one natural disaster (hurricane Katrina comes to mind) and all our sanitation infrastructure is gone.

gr8blessings

I read the same thing, and my conclusion is that vaccinating is the PROBLEM, not the solution.

[zylph]

Originally Posted by LindsayK

I was browsing through the reader comments of a pro-vaccine article on line the other day. One comment that made me think was a person who claimed that unvaccinated people serve as a repository of disease where the disease can mutate in the unvaccinated to become strains which aren't covered by vaccines. This would then endanger the vaccinated population, because the strains covered in the vaccine would no longer match the strains in the wild.

Is this true? Is there something that is missing in the argument?

This is true. I am not going to talk about mutation of the circulating OPV-derived polio strains because this is obviously a vaccine-caused problem (if OPV was not being used, it would not be circulating and mutating). Flu is probably a more helpful analogy here. One of the reasons that new strains of flu come out every year is largely due to the processes of antigenic shift and antigenic drift. Antigenic drift is the accumulation of random mutations in a manner roughly analogous to genetic drift. Antigenic shift requires an organism to be infected by two strains of flu, which then recombine their genomes to make something entirely new. These new flu strains can then evade immunity induced by previous flu infection or vaccination in other organisms, because their antigens are now too different to be recognized by antibodies/memory T cells.

Because flu is not endemic only in humans, we can look at birds and pigs as a model for an unvaccinated population. Even if we immunized everybody on the planet for all the flu strains now circulating in people (and the vaccines were 100% effective), we would still have flu the very next year. Because we have this large 'unvaccinated' population of birds and pigs where new strains of flu can be created.

Evolution does not 'anticipate' anything - there is no reason for the virus mutating. It just does. And to do so, it has to be able to productively infect something or somebody. Not all vaccines prevent transmission and no vaccine is 100% effective. But the viral and bacterial load (with the exception of vaccines against toxins - e.g., diphtheria) is going to be lower in vaccinated naive individuals than in unvaccinated naive individuals on a population level. So while both populations to some extent serve as 'reservoirs for mutation,' the vaccinated population is much less of one.

[amnesiac]

Just wanted to remind everyone to consider our guidelines for this forum when phrasing statements in this discussion:

rise to the occasion and opportunity to demonstrate the flaws, inconsistencies, and misinformation you feel are present in such information posted. Intelligent, informative, and civil debate should be the shining light of this forum without stooping to accusation, condescending comments and veiled insults against an individual's character or intentions in posting here ... While no one should be labeled as irresponsible or uninformed for deciding to vaccinate, neither should parents here who have chosen to not vaccinate be accused of irresponsibility, not caring for their child, or presenting a threat to others. Please respect each other and refrain from statements that are condescending, hurtful, judgmental, and belittling.

[MissRubyandKen]

Originally Posted by zylph

This is true. I am not going to talk about mutation of the circulating OPV-derived polio strains because this is obviously a vaccine-caused problem (if OPV was not being used, it would not be circulating and mutating). Flu is probably a more helpful analogy here. One of the reasons that new strains of flu come out every year is largely due to the processes of antigenic shift and antigenic drift. Antigenic drift is the accumulation of random mutations in a manner roughly analogous to genetic drift. Antigenic shift requires an organism to be infected by two strains of flu, which then recombine their genomes to make something entirely new. These new flu strains can then evade immunity induced by previous flu infection or vaccination in other organisms, because their antigens are now too different to be recognized by antibodies/memory T cells.

Because flu is not endemic only in humans, we can look at birds and pigs as a model for an unvaccinated population. Even if we immunized everybody on the planet for all the flu strains now circulating in people (and the vaccines were 100% effective), we would still have flu the very next year. Because we have this large 'unvaccinated' population of birds and pigs where new strains of flu can be created.

Evolution does not 'anticipate' anything - there is no reason for the virus mutating. It just does. And to do so, it has to be able to productively infect something or somebody. Not all vaccines prevent transmission and no vaccine is 100% effective. But the viral and bacterial load (with the exception of vaccines against toxins - e.g., diphtheria) is going to be lower in vaccinated naive individuals than in unvaccinated naive individuals on a population level. So while both populations to some extent serve as 'reservoirs for mutation,' the vaccinated population is much less of one.

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?