Uh, herd immunity??? Tell me your thoughts.

[JaneSmith1010]

Tell me your thoughts on herd immunity. According to my info there is no such thing.

[EVC]

I think it does not currently exist because adults are not so conscientious about keeping up with boosters, leaving the vast majority of people over, say, 30 without any immunity to VPDs. I actually think there would be a greater chance for achieving herd immunity if people did NOT vax so that children would get VPDs and then as adults WOULD carry immunity....

The problem with vax immunity is that it wears off....

[alegna]

It depends on the vaccine and the disease.

-Angela

[mamakay]

Originally Posted by alegna

It depends on the vaccine and the disease.

-Angela

Exactly.

[momto l&a]

Its amazing how many people have been vaccinated and then come down with whatever they where vaccinated for. So imo herd immunity doesn't exist.

[Plummeting]

Of course there is such a thing. It's why measles isn't killing unvaccinated babies left and right in America. They aren't getting protective passive immunity from their mothers, the vast majority of whom do not have immunity from natural infection themselves. Therefore, measles cannot possibly be happening in the US with any degree of regularity. If it were, infants would be dying. It's not happening. If there is no such thing as herd immunity, then where are all the American measles cases? Measles hasn't disappeared from the world. It's killing hundreds of thousands of kids in the developing world every year, so it's still out there. It probably wouldn't kill a healthy, well fed American kid, but if it was happening in the US, it would be killing babies. They aren't getting sufficient protective immunity from their mothers and the majority of them aren't even getting breastmilk. There's no way measles could be circulating widely in the US without killing infants.

The problem is that people have this idea that herd immunity means that no one will ever, ever catch any VPD if enough people are vaccinated. That simply isn't true. If you're not immune, either by successful response to vaccination or natural infection, and you're exposed to someone with a VPD, chances are very good that you're going to catch it. Having a million vaccinated people surrounding you isn't going to stop that from happening, if you're the first exposure. Herd immunity just means that there are enough people vaccinated to prevent disease circulation. And it might work for some diseases, if they could actually get enough people vaccinated with a highly effective vaccine.

One problem is that for every disease there is a certain threshold of people that must be immune (either through vaccination or infection) in order to stop disease circulation, but it's hard to reach that threshold for all of them. It's different for every disease, depending on a few factors. So if the threshold for measles is 92% (I don't remember what it is - just throwing a number out there) then 92% of people in a given population have to be immune in order to halt transmission of the disease in that group. If you vaccinate 95% of people, but the vaccine is only 90% effective, then only 85.5% of the population will be immune, which wouldn't be enough to halt disease transmission (in our fabricated scenario ). Furthermore, if you're successful in reaching the threshold for herd immunity, but are unable to create immunity in a full 100% of the population, there is always the possibility of a disease being imported from a place that hasn't stopped the circulation of disease in their area. It is much, much less likely if most people are immune, but as long as some people are not immune, it will always be possible. If a child from Germany (where measles is more common) is incubating measles and is infectious at the time she plays with my DD at the airport, my DD will catch measles if the exposure is enough. Herd immunity wouldn't protect her in that case. If, however, that child plays only with children who are immune due to vaccination, then the disease won't be spread, because those kids won't catch it. If those kids then play with my daughter the next few days, they aren't going to give her measles - herd immunity will prevent her from catching measles. If those kids weren't immune, they'd catch the virus, incubate it, then pass it on to my DD in those next few days. So yes, sometimes vaccine induced herd immunity absolutely does happen.

Then there are diseases like pertussis and diphtheria. The diphtheria vaccine does not prevent infection and carriage of the bacteria. Therefore, since any vaccinated individual can (and does) carry it from time to time, they are capable of transmitting it. If they can carry it and transmit it, they can't protect the unvaccinated from doing the same. Therefore, there can be no vaccine induced herd immunity to diphtheria. Same thing for pertussis as of right now. The vaccine doesn't work well enough to eliminate pertussis, no matter how many people they vaccinate.

So, yeah, it does depend on the disease.

[gilnikche]

Check out past responses. It is a frequent topic on this forum.

http://www.google.com/search?sourcei...+herd+immunity

[anewmama]

Originally Posted by momto l&a

Its amazing how many people have been vaccinated and then come down with whatever they where vaccinated for. So imo herd immunity doesn't exist.

What are you basing this on other than you "want it to be that way"?

[mammal_mama]

Originally Posted by anewmama

What are you basing this on other than you "want it to be that way"?

Since the poster you quoted was just sharing her thoughts as the OP requested, what's your problem?

[mammal_mama]

My thoughts about herd immunity are that it's probably not attributable to vaccines. Polio, for instance, had already started to decline before the advent of the vaccine (no, I don't have a direct citation, but you could probably find the info. through the National Vaccine Information Center).

I think some diseases just run their courses, and improvements in sanitation also help.

[mammal_mama]

Originally Posted by EVC

I actually think there would be a greater chance for achieving herd immunity if people did NOT vax so that children would get VPDs and then as adults WOULD carry immunity....

The problem with vax immunity is that it wears off....

Excellent point!

[applejuice]

In my personal life experience, I have encountered this term "herd immunity" from people who want to lay some guilt on me for the fact that I did not take the risk to be vaccinated. They did, and they are carrying the bulk of the risk to keep me healthy by being vaccinated for me.

B.S.

Life is full of risks. If artificial immunizations are preventative medicine, I will take my risks with disease, thank you very much. Read the package insert.

I think some diseases just run their courses, and improvements in sanitation also help.

Yes. So true.

Diseases come and diseases go. I had classmates lose entire years of school life because of an attack of scarlet fever, rheumatic fever, and mononucleosis. I have worked in the schools for thirty years and my children have just left school and I rarely hear of these diseases any longer. I have only heard of two outbreaks of 'scarletina' in the past twenty-five years, and milder form of the disease.

Where are those vaccines for scarlet fever, rheumatic fever, and bubonic plague?

[mammal_mama]

Originally Posted by applejuice

In my personal life experience, I have encountered this term "herd immunity" from people who want to lay some guilt on me for the fact that I did not take the risk to be vaccinated. They did, and they are carrying the bulk of the risk to keep me healthy by being vaccinated for me.

applejuice, that's exactly what our doctor tried to do to me -- lay guilt on me for not vaxing my girls. She even went so far as to say that vaccines are only effective when everyone in the community gets them.

If she really believes that, I wonder if she's "honest" and tells her other patients there's no point in them (or their kids) being vaxed since she knows at least 2 little girls around the corner whose stubborn momma is rendering everyone else's vaccines ineffective.

[applejuice]

We are not cows. We are human individuals.

[JaneSmith1010]

Originally Posted by anewmama

What are you basing this on other than you "want it to be that way"?

Thoughts please, not squabbling. If posters don't have opinions on herd immunity but do have opinions on other posters' opinions please state these nicely.

[JaneSmith1010]

Originally Posted by Plummeting

Of course there is such a thing. It's why measles isn't killing unvaccinated babies left and right in America. They aren't getting protective passive immunity from their mothers, the vast majority of whom do not have immunity from natural infection themselves. Therefore, measles cannot possibly be happening in the US with any degree of regularity. If it were, infants would be dying. It's not happening. If there is no such thing as herd immunity, then where are all the American measles cases? Measles hasn't disappeared from the world. It's killing hundreds of thousands of kids in the developing world every year, so it's still out there. It probably wouldn't kill a healthy, well fed American kid, but if it was happening in the US, it would be killing babies. They aren't getting sufficient protective immunity from their mothers and the majority of them aren't even getting breastmilk. There's no way measles could be circulating widely in the US without killing infants.

The problem is that people have this idea that herd immunity means that no one will ever, ever catch any VPD if enough people are vaccinated. That simply isn't true. If you're not immune, either by successful response to vaccination or natural infection, and you're exposed to someone with a VPD, chances are very good that you're going to catch it. Having a million vaccinated people surrounding you isn't going to stop that from happening, if you're the first exposure. Herd immunity just means that there are enough people vaccinated to prevent disease circulation. And it might work for some diseases, if they could actually get enough people vaccinated with a highly effective vaccine.

One problem is that for every disease there is a certain threshold of people that must be immune (either through vaccination or infection) in order to stop disease circulation, but it's hard to reach that threshold for all of them. It's different for every disease, depending on a few factors. So if the threshold for measles is 92% (I don't remember what it is - just throwing a number out there) then 92% of people in a given population have to be immune in order to halt transmission of the disease in that group. If you vaccinate 95% of people, but the vaccine is only 90% effective, then only 85.5% of the population will be immune, which wouldn't be enough to halt disease transmission (in our fabricated scenario ). Furthermore, if you're successful in reaching the threshold for herd immunity, but are unable to create immunity in a full 100% of the population, there is always the possibility of a disease being imported from a place that hasn't stopped the circulation of disease in their area. It is much, much less likely if most people are immune, but as long as some people are not immune, it will always be possible. If a child from Germany (where measles is more common) is incubating measles and is infectious at the time she plays with my DD at the airport, my DD will catch measles if the exposure is enough. Herd immunity wouldn't protect her in that case. If, however, that child plays only with children who are immune due to vaccination, then the disease won't be spread, because those kids won't catch it. If those kids then play with my daughter the next few days, they aren't going to give her measles - herd immunity will prevent her from catching measles. If those kids weren't immune, they'd catch the virus, incubate it, then pass it on to my DD in those next few days. So yes, sometimes vaccine induced herd immunity absolutely does happen.

Then there are diseases like pertussis and diphtheria. The diphtheria vaccine does not prevent infection and carriage of the bacteria. Therefore, since any vaccinated individual can (and does) carry it from time to time, they are capable of transmitting it. If they can carry it and transmit it, they can't protect the unvaccinated from doing the same. Therefore, there can be no vaccine induced herd immunity to diphtheria. Same thing for pertussis as of right now. The vaccine doesn't work well enough to eliminate pertussis, no matter how many people they vaccinate.

So, yeah, it does depend on the disease.

So, are you pro-vax (Sounds that way)? That is unique to see here. I have to ask where you get your info. I am still researching and have not come to the same conclusions as you have, but perhaps we have not crossed the same sources. You speak about successful responses to vaccination but I am wondering what exactly that entails. Again, I am curious and trying to sort out my info...not being snarky or defensive.

[applejuice]

There is room for disagreement with regards to artificial immunization. That is why this is called a discussion board. We all have our ideas.

I personally think the germ theory of disease is wrong. This is the basis for present day vaccination. I am sure we have progressed beyong this unfounded theory, and the Jenner concept should be relegated to the footnotes of quackery. There is too much $ invested in vaccines, though.

[JaneSmith1010]

Originally Posted by Plummeting

Of course there is such a thing. It's why measles isn't killing unvaccinated babies left and right in America. They aren't getting protective passive immunity from their mothers, the vast majority of whom do not have immunity from natural infection themselves. Therefore, measles cannot possibly be happening in the US with any degree of regularity. If it were, infants would be dying. It's not happening. If there is no such thing as herd immunity, then where are all the American measles cases? Measles hasn't disappeared from the world. It's killing hundreds of thousands of kids in the developing world every year, so it's still out there. It probably wouldn't kill a healthy, well fed American kid, but if it was happening in the US, it would be killing babies. They aren't getting sufficient protective immunity from their mothers and the majority of them aren't even getting breastmilk. There's no way measles could be circulating widely in the US without killing infants.

From what I have looked into many VPDs have phases or cycles in which they are dormant and then become virulent. Some, like polio, can be predicted but others seem a little more unpredictable. These virulence stages are incited by unknown triggers but they then send waves of the disease that travel to different global locations. No one knows why epidemics start and end, I have found no documentation of such knowlege.

Not only is this point not usually accounted for when people say that herd immunity is working but they also neglect to mention that many VPDs incidences have been declining naturally for the last 100+ years. I am not sure if this is particularly true with the measles but for diphtheria, whooping cough, scarlet fever it seems to be the case.

In other countries, you are right, inadequate nutrition and unsanitary living conditions are surely leaving babies susceptible to diseases and deaths still occur. Vax researcher Wendy Lydall states that nutrition is not a factor in whether or not someone gets a childhood disease, but good nutrition will affect the death rates.

Originally Posted by Plummeting

The problem is that people have this idea that herd immunity means that no one will ever, ever catch any VPD if enough people are vaccinated. That simply isn't true. If you're not immune, either by successful response to vaccination or natural infection, and you're exposed to someone with a VPD, chances are very good that you're going to catch it. Having a million vaccinated people surrounding you isn't going to stop that from happening, if you're the first exposure. Herd immunity just means that there are enough people vaccinated to prevent disease circulation. And it might work for some diseases, if they could actually get enough people vaccinated with a highly effective vaccine.

So here you are assuming that vaccinations will create immunity to a disease? Is this temp or lasting? The vax rate to achieve herd immunity to some disease (can't remember off the top of my head) started out at about 55% and has been raised steadily to about 95% after vaccinated people have come down with VPDs. I can give you references on this "fine tuning" if you like. Also, the index patients in outbreaks have sometimes been fully vaccinated individuals. Again, what a fully vaccinated individual is has changed after vaccinated persons have come down with VPDs, so that more booster shots are required. Another point would be what you define as a highly effective vaccine. If you are going by antibody reponse levels, have you read anything that indicates that this is all that is required for even temp immunity to a disease? I've been trying to find this info.

Originally Posted by Plummeting

One problem is that for every disease there is a certain threshold of people that must be immune (either through vaccination or infection) in order to stop disease circulation, but it's hard to reach that threshold for all of them. It's different for every disease, depending on a few factors. So if the threshold for measles is 92% (I don't remember what it is - just throwing a number out there) then 92% of people in a given population have to be immune in order to halt transmission of the disease in that group. If you vaccinate 95% of people, but the vaccine is only 90% effective, then only 85.5% of the population will be immune, which wouldn't be enough to halt disease transmission (in our fabricated scenario ). Furthermore, if you're successful in reaching the threshold for herd immunity, but are unable to create immunity in a full 100% of the population, there is always the possibility of a disease being imported from a place that hasn't stopped the circulation of disease in their area. It is much, much less likely if most people are immune, but as long as some people are not immune, it will always be possible. If a child from Germany (where measles is more common) is incubating measles and is infectious at the time she plays with my DD at the airport, my DD will catch measles if the exposure is enough. Herd immunity wouldn't protect her in that case. If, however, that child plays only with children who are immune due to vaccination, then the disease won't be spread, because those kids won't catch it. If those kids then play with my daughter the next few days, they aren't going to give her measles - herd immunity will prevent her from catching measles. If those kids weren't immune, they'd catch the virus, incubate it, then pass it on to my DD in those next few days. So yes, sometimes vaccine induced herd immunity absolutely does happen.

Then there are diseases like pertussis and diphtheria. The diphtheria vaccine does not prevent infection and carriage of the bacteria. Therefore, since any vaccinated individual can (and does) carry it from time to time, they are capable of transmitting it. If they can carry it and transmit it, they can't protect the unvaccinated from doing the same. Therefore, there can be no vaccine induced herd immunity to diphtheria. Same thing for pertussis as of right now. The vaccine doesn't work well enough to eliminate pertussis, no matter how many people they vaccinate.

So, yeah, it does depend on the disease.

Wow, that is confusing and very complicated. You're a reader huh? Me too Well, I'll have to read up on these things and see what I find. I'm interested in all this stuff. I'm not sure what to think of vaxes quite yet, but currenlty I am careful of them. I personally am not persuaded that they work as intended. Please don't take my responses to your post personally, I am only trying figure this stuff out. Thanks for your post.

[Gitti]

Originally Posted by jhow32000

Tell me your thoughts on herd immunity. According to my info there is no such thing.

Exactly my conclusion!

[mamakay]

Can I throw in my 2 cents?

Originally Posted by jhow

From what I have looked into many VPDs have phases or cycles in which they are dormant and then become virulent. Some, like polio, can be predicted but others seem a little more unpredictable. These virulence stages are incited by unknown triggers but they then send waves of the disease that travel to different global locations. No one knows why epidemics start and end, I have found no documentation of such knowlege.

With most epidemic peaks and cycles, I think it's a matter of a new, large population of "fresh" kids being born. Most of the highly contagious childhood diseases go in 5-10 year cycles. They'll explode for a couple of years, then slow down to a trickle for a while, then they'll be everywhere again for a while.
Diphtheria has some weird 100 year cycle, though, that no one understands. With bacteria, they evolve over time to outcompete other bacteria, so I think that might be part of it. But you're right...no one really knows for sure.

Not only is this point not usually accounted for when people say that herd immunity is working but they also neglect to mention that many VPDs incidences have been declining naturally for the last 100+ years. I am not sure if this is particularly true with the measles but for diphtheria, whooping cough, scarlet fever it seems to be the case.

Actually, whooping cough incidence appears to be as high as it ever was. We have about 3 million cases (at least) in the US right now. The organism that causes scarlet fever is still totally endemic, too(group A streptococcus). It's just acting milder now for whatever reason. The invention of abx has probably helped some, but I don't think that can be the only thing. A lot of bacteriologists think the bacteria has just evolved to be less virulent. I'd say fewer starving kids in the developed world might have made a difference, as well.

So here you are assuming that vaccinations will create immunity to a disease? Is this temp or lasting? The vax rate to achieve herd immunity to some disease (can't remember off the top of my head) started out at about 55% and has been raised steadily to about 95% after vaccinated people have come down with VPDs. I can give you references on this "fine tuning" if you like. Also, the index patients in outbreaks have sometimes been fully vaccinated individuals. Again, what a fully vaccinated individual is has changed after vaccinated persons have come down with VPDs, so that more booster shots are required. Another point would be what you define as a highly effective vaccine. If you are going by antibody reponse levels, have you read anything that indicates that this is all that is required for even temp immunity to a disease? I've been trying to find this info.

Creating herd immunity through vaccination is still a work in progress. Some vaccines totally fail at it (pertussis) but some are doing ok (measles).
About antibody responses...they're never quite right for predicting what will happen. I think the vax manufacturers get to set them anyway, a lot of the time.