Another herd immunity thread - Page 5

[mamakay]

Here something does not make sense to me. I do not think immune/not immune is the only part of the equation. For instance with the various bacteria that can cause meningitis, from what I understand they are in pretty much everyone's throats. But not everyone is coming down with meningitis. Why do some and not others? Why do 999 out of the infected 1000 not develop clinical polio? What makes that one person develop the clinical signs? What makes a person develop complications from measles, chickenpox, mumps?

Nobody really knows what all is going on there, but a lot of it is bad luck. Some is "host factors".
With polio, sometimes there was an injury that allowed the virus to gain access to the nervous system where it then caused paralysis. With meningitis, sometimes it's probably catching catching a nasty virus right at the same time they're newly colonized with a bacteria they've never been colonized with before. With chickenpox, a lot of times the severity of the illness is related to the "dose" of the virus the kid was exposed to.
But a lot of it is still just a mystery.

[shuttlt]

Originally Posted by ema-adama

OK, I think I am starting to understand where the differences in our approach come from. From what I understand you would be happy with a world where diseases were wiped out one after another leaving the population safer.

Sure, assuming it were possible, wouldn't everybody?

Originally Posted by ema-adama

I do not think everything else is detail.

Ironically I've been running a fever all day and it's making me flippant. More what I mean is that there are arguments about herd immunity were those things are irrelivant... is herd immunity theoretically possible, for example. There are then arguments where those things are much more important.... what place should herd immunity play in the fight against epidemic disease. My initial interest in this was people claiming that herd immunity was a myth. In answering that, it seems to me, nutrition isnt important.

Originally Posted by ema-adama

I think it is very significant as to just who is at risk of developing complication and/or dying.

Are you saying that if there was an outbreak in an industrialized, first world country nobody would die? In which case, surely one can have an argument about herd immunity without getting derailed by nutrition?

Originally Posted by ema-adama

Disease is a part of life and I am not sure that it can just be eradicated with vaccination (articificially - which I know is a difficult word, but I can't think of another).

There is no obvious way to eradicate disease in general, I agree. Equally, that doesn't mean there is no difference between now and 100 years ago.

Originally Posted by ema-adama

I just do not think it is that simple.

Neither do I.

Originally Posted by ema-adama

I still think that when addressing epidemiology and trying to figure out how best to protect a population, there are factors which doctors do not think are essential. It is almost as if some magic wand with no side effects is waved and voila, the disease is eradicated and we are a safer, healthier population. But is this really so?

Like what. Don't doctors say "eat healthily and take regular exercise". What aren't they addressing?

Originally Posted by ema-adama

When life long immunity is required for herd immunity, what else is long enough?

Sure. But is lifelong immunity required for herd immunity (I'm always focused on measles, but take your pick).

Originally Posted by ema-adama

Under what circumstances is a vaccine preferable?

If the harm of not vaccinating is juged to be greater than the harm of vaccinating. If you end up with fewer deaths total even if you shift them around a bit, it might be preferable. If you move the average age of getting the disease, but even for that age group you have fewer deaths.

Originally Posted by ema-adama

My understanding of shifting epidemiology is that babies are no longer protected by maternal antibodies and older people are more at risk for the diseases - the two segments of the population that you do not want sick with the diseases are now more at risk. I have to admit that this is more theoretical for me, as I do not have the numbers. This has been discussed here before (of course). If I have time I will try and dig it up.

But without numbers, all we know is that the average has moved. I don't care what the average is. It could be that the number of adults getting the illness has fallen as well, even though they now make up a greater proportion of people getting sick.

Originally Posted by ema-adama

What do you know about the nutritional needs of a child sick with measles and the recommended treatment? I have to assume you are thinking, please correct me if I am wronge, that it seems complete quackery to believe that something as simple as nutrition, clean water, clean (not disinfected) home environement etc can make that big of a difference in a healthy child.

I don't think it's quackery to say it can make a difference, how big, I don't know. Once they're sick I would presume it's a bit late for worrying about whether they are getting enough zinc. I don't see that saying this stuff can help means that herd immunity can't be important.

Originally Posted by ema-adama

That it can mean the different between life and disability/death.

If it makes any difference at all then I'm sure it can make the difference between life and death, sometimes. The question is how often.

[alegna]

Originally Posted by mamakay

What has me completely convinced that measles is really eliminated is the total and complete lack of measles death in infants. If an infant is deathly ill with a measles-like rash, they're going to test for measles. And in a "post vaccine society" it is infants who are most severely affected by measles when there's an epidemic.

I agree. It's either not around, OR infants are getting some passive immunity from mom prenatally.

-Angela

[Marnica]

This is an interesting thread that has made me wonder. I was vaccinated as a child with the MMR. I was born in 1972...if immunity is believed to be lifelong why was I required to receive a booster mmr at the age of 19 for college entry???

[carriebft]

Originally Posted by Marnica

This is an interesting thread that has made me wonder. I was vaccinated as a child with the MMR. I was born in 1972...if immunity is believed to be lifelong why was I required to receive a booster mmr at the age of 19 for college entry???

I don't know about your school, but the college I went to required an MMR booster if you had only had one dose or had no vaccination record.

[alegna]

Originally Posted by shuttlt

Sure, assuming it were possible, wouldn't everybody?

Nope. We're fooling with things we don't begin to understand. There is interesting research that shows that some childhood diseases prevent other chronic conditions. I also read an interesting article about how intestinal parasites prevent other chronic conditions. We don't know nearly enough about how the immune system works to start eliminating such huge factors.

-Angela

[amnesiac]

Originally Posted by Marnica

This is an interesting thread that has made me wonder. I was vaccinated as a child with the MMR. I was born in 1972...if immunity is believed to be lifelong why was I required to receive a booster mmr at the age of 19 for college entry???

The 2nd dose isnt considered a booster dose. But it was something that was paid a lot of attention to at that time beause of the measles outbreak that would have been wrapping up at the time you entered college.

[shuttlt]

Originally Posted by alegna

Nope. We're fooling with things we don't begin to understand. There is interesting research that shows that some childhood diseases prevent other chronic conditions. I also read an interesting article about how intestinal parasites prevent other chronic conditions. We don't know nearly enough about how the immune system works to start eliminating such huge factors.

-Angela

Is there any evidence that this is the case for stuff we vaccinate against? How man people might be effected if this is true? What chronic conditions are measles and mumps felt to protect against? Could you point me in the direction of information on this.

[ema-adama]

Originally Posted by shuttlt

Sure, assuming it were possible, wouldn't everybody?

Alegna addressed this nicely. When so little is understood, I have to say that mass vaccination could turn out to be a mass experiment.

what place should herd immunity play in the fight against epidemic disease. My initial interest in this was people claiming that herd immunity was a myth. In answering that, it seems to me, nutrition isnt important.

I personally do not think herd immunity is a myth. I think it is an extavagant idea to try to eliminate disease with vaccine induced herd immunity. Especially with waning immunity and the fact that the herd immunity argument is used to promote vaccines that are not producing herd immunity. These two things are red flags to me. Nutrition does not have anything to do with herd immunity. But it has everything to do with a healthy immune system. And the health of a population. And it is only relevant when looking at the foundations for promoting mass vaccination programmes. I guess I am challenging the assumption that only vaccination can make a society healthier and safer.

Are you saying that if there was an outbreak in an industrialized, first world country nobody would die? In which case, surely one can have an argument about herd immunity without getting derailed by nutrition?

No. There are people who are immune compromised. Even in the 1st world there are malnourished people. Am I understanding that you see the benefit of vaccine induced immunity as offering protection to those who do not look after the health of their families and those who are immune compromised?

Like what. Don't doctors say "eat healthily and take regular exercise". What aren't they addressing?

No. I was saying that when factoring in all the parametres for host, environment and pathogen to predict an epidemic, I do not know if such things are accurately factored in. Having a disease and being maimed/killed by the disease is not the same thing. Why was it assumed that vaccine induced immunity would result in herd immunity?

Sure. But is lifelong immunity required for herd immunity (I'm always focused on measles, but take your pick).

Just according the epidemic theory. What has made you think that anything less than life long immunity could contribute to herd immunity? I guess I should ask what you understand herd immunity to be.

If the harm of not vaccinating is juged to be greater than the harm of vaccinating. If you end up with fewer deaths total even if you shift them around a bit, it might be preferable. If you move the average age of getting the disease, but even for that age group you have fewer deaths.

This is where it gets interesting. Who can tell you what the harm is for vaccinating? Where is the honest discussion that any harm can happen? How do we know who is at risk of being harmed? Surely we need to have this information to make a risk/benefit analysis? But we are drifting from herd immunity again.

But without numbers, all we know is that the average has moved. I don't care what the average is. It could be that the number of adults getting the illness has fallen as well, even though they now make up a greater proportion of people getting sick.

Agreed, without the numbers this is a bit sensless to discuss.

I don't think it's quackery to say it can make a difference, how big, I don't know. Once they're sick I would presume it's a bit late for worrying about whether they are getting enough zinc. I don't see that saying this stuff can help means that herd immunity can't be important.

No, but once they are sick it might be worth while holding off on the paracetamol and look at vit C and A.

If it makes any difference at all then I'm sure it can make the difference between life and death, sometimes. The question is how often.

The studies are there.... time permitting I will try and track them down.

Originally Posted by alegna

Nope. We're fooling with things we don't begin to understand. There is interesting research that shows that some childhood diseases prevent other chronic conditions. I also read an interesting article about how intestinal parasites prevent other chronic conditions. We don't know nearly enough about how the immune system works to start eliminating such huge factors.

-Angela

:

[shuttlt]

Originally Posted by ema-adama

No. There are people who are immune compromised. Even in the 1st world there are malnourished people. Am I understanding that you see the benefit of vaccine induced immunity as offering protection to those who do not look after the health of their families and those who are immune compromised?

I'll address the rest of your post when I have a minute, but the above interested me. First off, I guess we can all agree that there are a large number of people who aren't going to give their children the nutrition that you are talking about. In some circumstances that can be to do with poverty, but I suspect in the UK/US it has more todo with 'choice'.

Second of all, is it the case that if your child is well nourished and isn't already sick with something else that these diseases are harmless? This seems to be an important question to have a definitive answer to. It clearly isn't true of smallpox for example, is it true of measles. If you infected 100,000 kids (who gave every outward sign of being healthy) with measles, would there be no deaths or serious complications? If this was the case, it would certainly cause me to reconsider my stance a little.

[ema-adama]

Originally Posted by shuttlt

I'll address the rest of your post when I have a minute, but the above interested me. First off, I guess we can all agree that there are a large number of people who aren't going to give their children the nutrition that you are talking about. In some circumstances that can be to do with poverty, but I suspect in the UK/US it has more todo with 'choice'.

DS is sleeping and I am ignoring my messy house... but I'll give it a shot. Yes, in the 1st world it is about 'choice' and again, parents not having information.

Second of all, is it the case that if your child is well nourished and isn't already sick with something else that these diseases are harmless?

I think we need to understand the word 'harmless'. I take it to mean no lasting problems and no death.

I realise that it might be a copyright problem for me to type up what I have as it is from a book and not an online article.If you really want to read some articles on this, I suggest you track down a book called Just A Little Prick which has a wealth of information on measles and what the personal risk factors are and the best treatment. From medical literature.

This seems to be an important question to have a definitive answer to. It clearly isn't true of smallpox for example, is it true of measles. If you infected 100,000 kids (who gave every outward sign of being healthy) with measles, would there be no deaths or serious complications? If this was the case, it would certainly cause me to reconsider my stance a little.

The parameters that I have understood to be important in a positive outcome following a measles infection are the following:
Good nutrition (worth defining, BTW. I have no idea of what your idea of good nutrition is)
Supplementing with vit A when ill with the measles.
A healthy immune system (again, worth defining)
A clean, non-toxic environment (again, this could be different for different people)
Not dosing the fever with paracetamol or other fever surpressors.
Learning the skills to manage a fever.
A doctor who is not running scared when treating measles, but monitoring for any complications and treating them as the need arises.
Parents confident in their ability to take care of a sick child.

Rather utopian. Not easy to find a population like this. And it sounds like an awful lot of hard work for authorities to create a population like this when there is a cheap, easy vaccine. (with unkown risks and no discussion on what those risks might be, how to prevent them, who is at risk and whether vaccine induced immunity is ever going to live up to the expectations)

But we have strayed very far away from herd immunity. And somehow ended up talking about measles. There are many many other vaccines out there.

What is your stance?

[shuttlt]

Originally Posted by ema-adama

But we have strayed very far away from herd immunity. And somehow ended up talking about measles. There are many many other vaccines out there.

Yes, I'd like to keep this focused on herd immunity. I keep talking about measles only to restrict the discussion to try to avoid one person talking about herd immunity for flu, while another talks about herd immunity for smallpox. I don't really care about measles, I just thought by trying to understand what people thought about herd immunity for measles and only measles, I would get a clearer understanding without getting bogged down in the specifics of every vaccine on the market. I only chose measles as it is topical, and hopefully sufficiently representative of the argument as a whole.

[shuttlt]

Originally Posted by ema-adama

DS is sleeping and I am ignoring my messy house... but I'll give it a shot. Yes, in the 1st world it is about 'choice' and again, parents not having information.

I take it you mean, not enough information, in the sense that better nutrition isn't talked about in the context of vaccination? It certainly is talked about and encouraged outside of this context.

Originally Posted by ema-adama

I think we need to understand the word 'harmless'. I take it to mean no lasting problems and no death.

I'm happy with that definition.

Originally Posted by ema-adama

I realise that it might be a copyright problem for me to type up what I have as it is from a book and not an online article.

Copyright wise, depending on how much you quote, you'd probably be fine. This forum may have rules over and above that.

Originally Posted by ema-adama

If you really want to read some articles on this, I suggest you track down a book called Just A Little Prick which has a wealth of information on measles and what the personal risk factors are and the best treatment. From medical literature.

I may well do that.

Originally Posted by ema-adama

The parameters that I have understood to be important in a positive outcome following a measles infection are the following:
Good nutrition (worth defining, BTW. I have no idea of what your idea of good nutrition is)
Supplementing with vit A when ill with the measles.
A healthy immune system (again, worth defining)
A clean, non-toxic environment (again, this could be different for different people)
Not dosing the fever with paracetamol or other fever surpressors.
Learning the skills to manage a fever.
A doctor who is not running scared when treating measles, but monitoring for any complications and treating them as the need arises.
Parents confident in their ability to take care of a sick child.

All good things, which I am sure will result in more positive outcomes.

Originally Posted by ema-adama

Rather utopian. Not easy to find a population like this. And it sounds like an awful lot of hard work for authorities to create a population like this when there is a cheap, easy vaccine. (with unkown risks and no discussion on what those risks might be, how to prevent them, who is at risk and whether vaccine induced immunity is ever going to live up to the expectations)

I think a lot of people would choose cheap vaccines over making lifestyle choices. Some people choose to eat McDonalds and do no exercise, I'm not sure how one can deal with this and respect their choice. I would definately agree with you utopian criticism.

Originally Posted by ema-adama

But we have strayed very far away from herd immunity. And somehow ended up talking about measles. There are many many other vaccines out there.

What is your stance?

Well, this stuff is relevant to herd immunity in as much as I thought you were offering it as an alternative. I had understood your case to be that herd immunity wasn't necessary in the developed world because, so long as people were healthy and well nourished, all doctors had to do was refocus on supporting people though childhood illness and nobody would be harmed. As you admit, it is unlikely that everybody in the population will be healthy and well nourished. I'm interested in your claim that healthy people (can we define that as people who appear healthy and who are well nourished) do not suffer perminant damage from common childhood illnesses.

[ema-adama]

I don't want to monopolize the thread.

Perhaps it will help to discuss whether life long immunity is indeed relevant to herd immunity and also to discuss which vaccines could or could not contribute to herd immunity, and why. (as I do no think that measles and the measles vaccine can be representative of the herd immunity argument for any other disease or vaccine other than measles itself).

[carriebft]

I think it is impossible to talk about herd immunity without breaking it down into which vaccines work for herd immunity, which are SUPPOSE to (and perhaps argue why they do or don't-- think varicella) and those that cannot create herd immunity.

I suppose I would add another category of those that create herd immunity but have trouble when immunity wanes-- mumps? rubella? I would have to look at the evidence.


Also we can look at hib and prevnar as vaccines in the transmission/herd immunity argument. IMO, these are like measles but with their own unique issues (serotype replacement)

[shuttlt]

Originally Posted by ema-adama

I don't want to monopolize the thread.

OK. I realize we all either have jobs to do, and/or children to look after. I've been enjoying your posts, so I hope you're not going to back away completely.

Originally Posted by ema-adama

Perhaps it will help to discuss whether life long immunity is indeed relevant to herd immunity and also to discuss which vaccines could or could not contribute to herd immunity, and why.

Hopefully, I've answered that now.

Originally Posted by ema-adama

(as I do no think that measles and the measles vaccine can be representative of the herd immunity argument for any other disease or vaccine other than measles itself).

Perhaps not. My fear is that if it becomes about all vaccines, one ends up with all people are unique, every vaccine is different and it becomes much harder to pin it down to numbers so that people (myself included) are actually forced to be specific and concrete about what they mean.

[alegna]

Originally Posted by shuttlt

Is there any evidence that this is the case for stuff we vaccinate against? How man people might be effected if this is true? What chronic conditions are measles and mumps felt to protect against? Could you point me in the direction of information on this.

I don't have the links marked, but there is some interesting research out there. Measles I know has been linked with something- can't remember what for the life of me right now Hopefully someone will be along with a link.

-Angela

[ema-adama]

Originally Posted by shuttlt

I take it you mean, not enough information, in the sense that better nutrition isn't talked about in the context of vaccination? It certainly is talked about and encouraged outside of this context.

Nope, I meant that there are a variety of understandings as to what constitutes good nutrition. It means very different things to different people.

I think a lot of people would choose cheap vaccines over making lifestyle choices. Some people choose to eat McDonalds and do no exercise, I'm not sure how one can deal with this and respect their choice. I would definately agree with you utopian criticism.

But would they choose the said vaccine if they knew exactly what the risks were and knew if their child was at risk and if the child was at risk, what would minimize that risk?

Well, this stuff is relevant to herd immunity in as much as I thought you were offering it as an alternative. I had understood your case to be that herd immunity wasn't necessary in the developed world because, so long as people were healthy and well nourished, all doctors had to do was refocus on supporting people though childhood illness and nobody would be harmed. As you admit, it is unlikely that everybody in the population will be healthy and well nourished. I'm interested in your claim that healthy people (can we define that as people who appear healthy and who are well nourished) do not suffer perminant damage from common childhood illnesses.

I don't think I ever said herd immunity was not necessary in the developed world. I have said that I do not know how beneficial vaccine induced herd immunity would be, taking waning immunity into consideration, and that not all vaccines are even capable of creating herd immunity. Naturally acquired immunity in childhood would provide herd immunity, theoretically anyway.
And this takes us back to the idea that the whole population recquires vaccination to protect malnourished and sickly children.

Originally Posted by carriebft

I think it is impossible to talk about herd immunity without breaking it down into which vaccines work for herd immunity, which are SUPPOSE to (and perhaps argue why they do or don't-- think varicella) and those that cannot create herd immunity.

I suppose I would add another category of those that create herd immunity but have trouble when immunity wanes-- mumps? rubella? I would have to look at the evidence.


Also we can look at hib and prevnar as vaccines in the transmission/herd immunity argument. IMO, these are like measles but with their own unique issues (serotype replacement)

All good points. I have been thinking about hib and prevnar, and with the numbers of children being affected from menigitis not really changing, it's a kind of herd immunity, but one that doesn't mean anything in real life, and only makes things more complicated and possibly even dangerous.

Originally Posted by shuttlt

OK. I realize we all either have jobs to do, and/or children to look after. I've been enjoying your posts, so I hope you're not going to back away completely.

If the dog stays quiet and DS keeps sleeping, I might actually get this post done. I've also been enjoying your posts and I think this thread is very interesting.

I am still curious as to why you think life long immunity is not essential to herd immunity.

Perhaps not. My fear is that if it becomes about all vaccines, one ends up with all people are unique, every vaccine is different and it becomes much harder to pin it down to numbers so that people (myself included) are actually forced to be specific and concrete about what they mean.

I can see your point. However, as carriebft pointed out, you just cannot discuss herd immunity from vaccinations without going into each disease and the vaccine as they are unique. And 'unfortunatly' all people are unique. The only thing I think you can discuss without going into specifics is why herd immunity would work with anything less than life long immunity.

[Ophelia]

Originally Posted by alegna

I don't have the links marked, but there is some interesting research out there. Measles I know has been linked with something- can't remember what for the life of me right now Hopefully someone will be along with a link.

-Angela

This?

http://www.ncbi.nlm.nih.gov/pubmed/1...?dopt=Abstract

There are data to suggest that measles, hepatitis A, and Mycobacterium tuberculosis infection in early life may prevent the subsequent development of atopic diseases

[shuttlt]

Originally Posted by ema-adama

Nope, I meant that there are a variety of understandings as to what constitutes good nutrition. It means very different things to different people.

What do you mean by it?

Originally Posted by ema-adama

But would they choose the said vaccine if they knew exactly what the risks were and knew if their child was at risk and if the child was at risk, what would minimize that risk?

It probably depends how you ask the question. People still feed their children junk even though they have been told the harm it does. I don't see that they would necessarily behave differently. Also, the issue is complicated and a lot of people are not going to want to bother. I've put quite a few hours into this, and I'm in no position to make an informed judgement.

Originally Posted by ema-adama

I don't think I ever said herd immunity was not necessary in the developed world.

Sorry. I'll take down the straw mother

Originally Posted by ema-adama

I have said that I do not know how beneficial vaccine induced herd immunity would be, taking waning immunity into consideration, and that not all vaccines are even capable of creating herd immunity.

By waning immunity, do you mean something todo with people who are immune because they caught the virus in the wild are more immune than people who have been vaccinated, hence waning immunity as fewer and fewer people encounter it. Or, do you mean something else? In my ignorance I am unsure.

As for not all vaccines being considered capable of herd immunity. Presumably that is an accepted fact that even the WHO would fully support.

Originally Posted by ema-adama

Naturally acquired immunity in childhood would provide herd immunity, theoretically anyway.

That is a totally different kind of herd immunity. In that herd immunity you have continuously circulating illnesses and epidemics.

Originally Posted by ema-adama

And this takes us back to the idea that the whole population recquires vaccination to protect malnourished and sickly children.

Which is true, but I have yet to be convinced that it is only children that you know are sick who are at risk. Viruses are like vaccines in this respect. In either case there is a very small risk of something bad happening. It will always be the case that that bad thing happened for a reason, whether it is a Mitochondrial problem, or malnutrition. The question is whether these things are identifiable ahead of time. Every single measles death that there has ever been is because the person who died was weaker in some respect than others who lived, unless you are able to identify these people ahead of time that does you no good. The number of people who would get infected if you stopped vaccinating is so huge that you are bound to find people who are weak in some respect without anybody knowing. What you need to do it quantify it.

Originally Posted by ema-adama

I am still curious as to why you think life long immunity is not essential to herd immunity.

Anything less than lifelong immunity has the effect of reducing the percentage of people in the population who are immune. If that number is reduced past the percentage you need for herd immunity, it's a problem and you need a booster, if not it's not a problem.

Originally Posted by ema-adama

I can see your point. However, as carriebft pointed out, you just cannot discuss herd immunity from vaccinations without going into each disease and the vaccine as they are unique. And 'unfortunatly' all people are unique. The only thing I think you can discuss without going into specifics is why herd immunity would work with anything less than life long immunity.

But many people on the forum seem to reject herd immunity out of hand. Have they considered it and found different reasons for every vaccine, is there really no general argument against herd immunity? Do we all agree that herd immunity for some stuff we vaccinate for works and is a good thing? Must we discuss every disease that we vaccinate against in order to discuss herd immunity?

As for all people being unique, sure we are unique, but on a bell curve. There is a lot we have in common, a lot that we can say in general and bounds on our uniqueness.