Another herd immunity thread - Mothering Forums
Forum Jump: 
Reply
 
Thread Tools
#1 of 113 Old 02-23-2009, 07:12 PM - Thread Starter
 
shuttlt's Avatar
 
Join Date: Feb 2009
Posts: 516
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I've read a few of the old threads on herd immunity and none of them quite seemed to pin it all down for me. I was hoping someone would be good enough to show me where the two camps disagree.

From what I can gather herd immunity can be stipped down to a mathematical argument:The_mathematics_of_mass_vaccination
I wondered whether there is anybody who feels the mathematics that herd immunity is based on is flawed?

If the maths isn't flawed, I wondered whether anybody disagreed with the numbers being pumped in?

If you don't disagree with the theory of herd immunity, I wondered if you disagreed with the figures for vaccination rates that pro-vaxers are forever claiming are too low?

One of the reasons this interests me so much is that most of the pro-vax position rests on herd immunity, which you folks regard as being obviously false. If you demolish it, you win. I kind of suspect since the pro-vax position is still the party line that in fact the herd immunity debate comes down to rival sources of authority for the numbers.
shuttlt is offline  
#2 of 113 Old 02-23-2009, 07:34 PM
 
kiara7's Avatar
 
Join Date: Feb 2008
Posts: 1,044
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I disagree with vaccine-induced herd immunity argument. There have been examples of natural herd immunity to diseases, i.e. chicken pox. The vast majority had it in childhood and developed natural lifelong immunity. Then adults are periodically re-exposed to it through their own children and grandchildren for natural boosters. That is the herd immunity.

Whether formulas and math are right or wrong is irrelevant. The pro-vax herd immunity argument is flawed because it's based on flawed assumptions that vaccines are 95 or 100% effective (which they are not), that viruses and bacteria don't mutate in order to survive (which they do), and that everyone will agree to take a possibility of damaging their child for the greater good and bring him to the "altar" for the sake of the herd (which many do not).
kiara7 is offline  
#3 of 113 Old 02-23-2009, 08:01 PM - Thread Starter
 
shuttlt's Avatar
 
Join Date: Feb 2009
Posts: 516
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by kiara7 View Post
I disagree with vaccine-induced herd immunity argument. There have been examples of natural herd immunity to diseases, i.e. chicken pox. The vast majority had it in childhood and developed natural lifelong immunity. Then adults are periodically re-exposed to it through their own children and grandchildren for natural boosters. That is the herd immunity.
That would certainly be one form of it. I guess the same maths would describe what's going on there.

Quote:
Originally Posted by kiara7 View Post
Whether formulas and math are right or wrong is irrelevant.
There is no question that it is irrelivant to why many people do not vax. It's relevant to me, as these are the terms in which I think. I would assume it's relevant to the wider debate between the two viewpoints. As I've said many times, I come from a naively pro-vax background and I would welcome having my world shaken.

Quote:
Originally Posted by kiara7 View Post
The pro-vax herd immunity argument is flawed because it's based on flawed assumptions that vaccines are 95 or 100% effective (which they are not), that viruses and bacteria don't mutate in order to survive (which they do),
OK. So you disagree with the numbers going in to the formula? I'll try and flesh out the numbers relating to the official figures so we can be more specific about the disagreement.

Quote:
Originally Posted by kiara7 View Post
and that everyone will agree to take a possibility of damaging their child for the greater good and bring him to the "altar" for the sake of the herd (which many do not).
OK. This is more like a disagreement with the official figures for vaccination rates. Do you disagree that, for the sake of argument, measles vaccination rates were above the critical herd immunity rate until recently in the UK? I presume you must in order to justify your statement.
shuttlt is offline  
#4 of 113 Old 02-23-2009, 08:05 PM
Banned
 
Join Date: Nov 2008
Location: Ohio
Posts: 722
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
That entry on wikipedia is very interesting (I : math). I agree with the mathematical analysis of it entirely - my problem is with the title. The major flaw is that it uses "vaccination" and "immunity" interchangeably. If you read the article as the mathematics of immunity it clearly explains the theory of active, natural herd immunity. This however does not translate into an accurate description of active, artificial immunity.

If we describe immunity as (from wikipedia): "Immunity is a medical term that describes a state of having sufficient biological defenses to avoid infection, disease, or other unwanted biological invasion." Then natural herd immunity postulates that in the presence of sufficient biological defenses in a critical mass of individuals a whole population will be protected. The logical leap can not be made that this automatically equates to sufficient vaccination rates in a critical mass...

Herd Immunity:
if individual immunity = or > critical mass then pathogen can not propagate ergo natural herd immunity.

is different than what pro-vax claims:
if # of vaccinated individuals = or > critical mass then pathogen can not propogate

This is missing a big variable: level of acquired immunity per individual. For herd immunity to be proven to me I would need:
if vaccinated individuals attain level x of active artificial immunity ("sufficient biological defense") AND these individuals make up (= or >) a required critical mass of the population then pathogen can not propagate ergo artificial herd immunity.

Sadly, wikipedia's entry on herd immunity does not even discuss the natural biologic process of herd immunity but only the theory of vaccine-induced herd immunity (in fact, it is hard to find information on herd immunity in a non-vaccine light anywhere online). The mix up (intentional or not) of vaccine and immune is a huge part of the divide between pro and anti-vax people IMO.
PaigeC is offline  
#5 of 113 Old 02-23-2009, 08:23 PM
 
runes's Avatar
 
Join Date: Aug 2004
Posts: 5,177
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
It is fundamentally flawed to talk about herd immunity as a concept that is removed from specific vaccines/diseases. All vaccines don't work the same way, and the diseases have different criteria, incubation periods, contagious periods etc. that have a major impact on how it is spread.

For example, one major factor in smallpox "eradication" was quarantine, not vaccination. Since a person that has contracted smallpox is only contagious after the rash manifests, the case can be identified and quarantined in an appropriate and timely manner to reduce or eliminate transmission.

Other vaccines, like the DTaP, don't prevent transmission, because they are not supposedly building immunity against the bacteria that cause these diseases, but the toxins that this bacteria emit.

Also not being accounted for is live virus vaccines. As long as there are live virus vaccines, I personally believe that the disease will never be "eradicated", as shedding is a real concern.

And the article that you link to does mention shifting epidemiology:

Quote:
However, it is important to consider this effect when vaccinating against diseases which increase in severity with age. A vaccination programme against such a disease that does not exceed qc may cause more deaths and complications than there were before the programme was brought into force as individuals will be catching the disease later in life. These unforeseen outcomes of a vaccination programme are called perverse effects.
although this is not a full analysis of the phenomenon. You can look for some information regarding measles, maternal antibodies and infants.

So the math that is in your link might be THEORETICALLY correct, but are not necessarily applicable in real life. And in the end, isn't that what really counts?
runes is offline  
#6 of 113 Old 02-23-2009, 08:25 PM
 
kiara7's Avatar
 
Join Date: Feb 2008
Posts: 1,044
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The problem as PaigeC pointed out very clearly is the assumption that vaccine-induced "immunity" is the same as natural immunity. That is the first assumption that the rest of the argument is based on. This is false. The math may be right down the line, but based on a false assumption any conclusions are false too.
kiara7 is offline  
#7 of 113 Old 02-23-2009, 08:30 PM - Thread Starter
 
shuttlt's Avatar
 
Join Date: Feb 2009
Posts: 516
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by PaigeC View Post
Herd Immunity:
if individual immunity = or > critical mass then pathogen can not propagate ergo natural herd immunity.

is different than what pro-vax claims:
if # of vaccinated individuals = or > critical mass then pathogen can not propogate
I was concentrating mainly on measles where they seemed to be quoting very high rates:
Quote:
Originally Posted by CDC
Most children who get the vaccine develop immunity to all three diseases (over 99% for measles and 95% for mumps and rubella). Protection is believed to be life-long.
http://www.cdc.gov/vaccines/vpd-vac/...cc_measles.pdf

Is this another case of I have my sources of authoritative facts, and you have yours?

Quote:
Originally Posted by PaigeC View Post
This is missing a big variable: level of acquired immunity per individual.
I'm going to have to go away, scratch my head and read more to be sure whether it's missing or significant. Right now I'm not certain one way or the other.

Quote:
Originally Posted by PaigeC View Post
Sadly, wikipedia's entry on herd immunity does not even discuss the natural biologic process of herd immunity but only the theory of vaccine-induced herd immunity (in fact, it is hard to find information on herd immunity in a non-vaccine light anywhere online). The mix up (intentional or not) of vaccine and immune is a huge part of the divide between pro and anti-vax people IMO.
That's kind of what I want nailing the maths to help me to understand.
shuttlt is offline  
#8 of 113 Old 02-23-2009, 08:38 PM - Thread Starter
 
shuttlt's Avatar
 
Join Date: Feb 2009
Posts: 516
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by kiara7 View Post
The problem as PaigeC pointed out very clearly is the assumption that vaccine-induced "immunity" is the same as natural immunity.
And that's fine. Is this a fact that would be disputed, or accepted by the CDC?

Quote:
Originally Posted by kiara7 View Post
That is the first assumption that the rest of the argument is based on. This is false.
I need to get the figures they are pumping into the formula to be absolutely sure what the mean by immunity.

Quote:
Originally Posted by kiara7 View Post
The math may be right down the line, but based on a false assumption any conclusions are false too.
No arguing with that.
shuttlt is offline  
#9 of 113 Old 02-23-2009, 08:50 PM - Thread Starter
 
shuttlt's Avatar
 
Join Date: Feb 2009
Posts: 516
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by kidspiration View Post
It is fundamentally flawed to talk about herd immunity as a concept that is removed from specific vaccines/diseases.
OK. Measles is a topical one.

Quote:
Originally Posted by kidspiration View Post
Also not being accounted for is live virus vaccines. As long as there are live virus vaccines, I personally believe that the disease will never be "eradicated", as shedding is a real concern.
Is measles in MMR live virus? I've got an idea it is.

Quote:
Originally Posted by kidspiration View Post
And the article that you link to does mention shifting epidemiology:
Sure, that is an acknowledged problem with vaccination programs that fail to reach herd immunity. I don't think that is disputed.

Quote:
Originally Posted by kidspiration View Post
So the math that is in your link might be THEORETICALLY correct, but are not necessarily applicable in real life. And in the end, isn't that what really counts?
The maths, as I understand it is what the pro-vax case is based on. I want to understand why it is wrong. Sure the real world is what counts, but it is wooly and ill defined, arguments about it can go on and on without ever getting anywhere. Some aspects can be expressed in terms of maths, the real question is, are those aspects important.
shuttlt is offline  
#10 of 113 Old 02-23-2009, 08:53 PM
 
alegna's Avatar
 
Join Date: Jan 2003
Posts: 44,408
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Also, it's important to remember, that herd immunity can only apply to diseases where the vaccine prevents transmission.

-Angela
alegna is offline  
#11 of 113 Old 02-23-2009, 08:56 PM - Thread Starter
 
shuttlt's Avatar
 
Join Date: Feb 2009
Posts: 516
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by alegna View Post
Also, it's important to remember, that herd immunity can only apply to diseases where the vaccine prevents transmission.

-Angela
Agreed. No herd immunity for tetinus.
shuttlt is offline  
#12 of 113 Old 02-23-2009, 09:06 PM - Thread Starter
 
shuttlt's Avatar
 
Join Date: Feb 2009
Posts: 516
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by kidspiration View Post
Also not being accounted for is live virus vaccines. As long as there are live virus vaccines, I personally believe that the disease will never be "eradicated", as shedding is a real concern.
In as much as so long as there is a possibility of secondary transmission the disease won't be eradicated, I agree. I disagree that this isn't taken account in the maths. A secondary transmission is just a case of infection that may, or may not manage to infect >=1 other person and start an outbreak.
shuttlt is offline  
#13 of 113 Old 02-23-2009, 09:13 PM
 
kiara7's Avatar
 
Join Date: Feb 2008
Posts: 1,044
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by shuttlt View Post
The maths, as I understand it is what the pro-vax case is based on. I want to understand why it is wrong. Sure the real world is what counts, but it is wooly and ill defined, arguments about it can go on and on without ever getting anywhere. Some aspects can be expressed in terms of maths, the real question is, are those aspects important.

We need to figure out the difference between natural immunity and vaccine immunity, in numbers. I don't have time to look this up, but if you're up for it, I'm sure we'll have a very good discussion.
kiara7 is offline  
#14 of 113 Old 02-23-2009, 09:22 PM - Thread Starter
 
shuttlt's Avatar
 
Join Date: Feb 2009
Posts: 516
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by kiara7 View Post
We need to figure out the difference between natural immunity and vaccine immunity, in numbers. I don't have time to look this up, but if you're up for it, I'm sure we'll have a very good discussion.
If I turn some numbers up, I'll most definately post them. You all probably have the advantage of me on finding them as there being a difference is fairly new on me. People keep talking as if artifical immunity fades, but that isn't what the CDC says (as previously quoted):
Quote:
Originally Posted by CDC
Most children who get the vaccine develop immunity to all three diseases (over 99% for measles and 95% for mumps and rubella). Protection is believed to be life-long.
If it's lifelong and 99% effective (in the case of measles), I don't see where there is much room for a natural immunity to do much better. Perhaps, how many children they mean by 'most' is where the difference lies?
shuttlt is offline  
#15 of 113 Old 02-23-2009, 09:24 PM
 
anewmama's Avatar
 
Join Date: Feb 2007
Posts: 1,530
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by shuttlt View Post
One of the reasons this interests me so much is that most of the pro-vax position rests on herd immunity, which you folks regard as being obviously false.
I don't think it is absolutely false. I think there are flaws and questions, but I don't think I could ever throw it out entirely as some have.
anewmama is offline  
#16 of 113 Old 02-23-2009, 09:27 PM - Thread Starter
 
shuttlt's Avatar
 
Join Date: Feb 2009
Posts: 516
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Apologies for the storm of posts. I realized I'm confused about something:
"Most children who get the vaccine develop immunity to all three diseases (over 99% for measles and 95% for mumps and rubella). "
Does this mean most children are 99% protected, or 99% of children are completely protected? I'm looking, but the CDC faq didn't make it clear.
shuttlt is offline  
#17 of 113 Old 02-23-2009, 09:28 PM
 
anewmama's Avatar
 
Join Date: Feb 2007
Posts: 1,530
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by kiara7 View Post
There have been examples of natural herd immunity to diseases, i.e. chicken pox. The vast majority had it in childhood and developed natural lifelong immunity. Then adults are periodically re-exposed to it through their own children and grandchildren for natural boosters. That is the herd immunity.
I don't disagree with the idea that children get it and adults' immunity is reinforced. But there is no herd immunity here in my opinion because it is still a circulating disease which children get. Or should I say was before the vax?

The way it used to work the way I see it is there was only partial herd immunity with adults carrying on immunity after childhood exposure. The only part of the herd being mostly protected is adults. But the idea that adults are immune and that might protect kids doesn't work so there is no total herd immunity. Or was. Hard to talk about this one as there is a vax!
anewmama is offline  
#18 of 113 Old 02-23-2009, 09:30 PM
 
runes's Avatar
 
Join Date: Aug 2004
Posts: 5,177
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by shuttlt View Post
Is measles in MMR live virus? I've got an idea it is.
Yes. All 3 in the MMR...measles, mumps and rubella, are live virus vaccines.

As is varicella (chicken pox), rotovirus, oral polio and Flumist.

Quote:
Originally Posted by shuttlt View Post
Sure, that is an acknowledged problem with vaccination programs that fail to reach herd immunity. I don't think that is disputed.
Shifting epidemiology occurs whether the vaccine program "reaches" herd immunity or not. Case in point...chicken pox.

Quote:
Originally Posted by shuttlt View Post
The maths, as I understand it is what the pro-vax case is based on. I want to understand why it is wrong. Sure the real world is what counts, but it is wooly and ill defined, arguments about it can go on and on without ever getting anywhere. Some aspects can be expressed in terms of maths, the real question is, are those aspects important.
If you are asking if the key concepts of epidemiology can be boiled down to the math, and if this math is either correct or relevant, my original assertion still stands. It is a lot more complicated than a bunch of mathematical formulae.

For example, how do they account for asymptomatic and subclinical cases? Certainly they won't figure in the math, and they won't count as a clinical "case" but it sure does factor into the epidemiology.

If you are planning to vax for the MMR, are you going to get titres drawn after vaccination and every year afterward to see if your child is immune? Why or why not?
runes is offline  
#19 of 113 Old 02-23-2009, 09:31 PM - Thread Starter
 
shuttlt's Avatar
 
Join Date: Feb 2009
Posts: 516
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by anewmama View Post
I don't think it is absolutely false. I think there are flaws and questions, but I don't think I could ever throw it out entirely as some have.
Apologies, it can be a little too easy to tar everybody with the same brush. The spectrum here goes from the odd pro-vaxer right the way to people who don't subscribe to the conventional model of disease.
shuttlt is offline  
#20 of 113 Old 02-23-2009, 09:32 PM
 
alegna's Avatar
 
Join Date: Jan 2003
Posts: 44,408
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by shuttlt View Post
Agreed. No herd immunity for tetinus.
(Right, since tetanus isn't a communicable disease in the first place )


Or pertussis.

Or probably diphtheria

Or polio with the current vax.

-Angela
alegna is offline  
#21 of 113 Old 02-23-2009, 09:32 PM
 
Proverbs31's Avatar
 
Join Date: Aug 2006
Posts: 602
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by shuttlt View Post
Apologies for the storm of posts. I realized I'm confused about something:
"Most children who get the vaccine develop immunity to all three diseases (over 99% for measles and 95% for mumps and rubella). "
Does this mean most children are 99% protected, or 99% of children are completely protected? I'm looking, but the CDC faq didn't make it clear.
It means that percentage develop an adequate level of antibodies.
Proverbs31 is offline  
#22 of 113 Old 02-23-2009, 09:32 PM
 
runes's Avatar
 
Join Date: Aug 2004
Posts: 5,177
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by shuttlt View Post
Apologies for the storm of posts. I realized I'm confused about something:
"Most children who get the vaccine develop immunity to all three diseases (over 99% for measles and 95% for mumps and rubella). "
Does this mean most children are 99% protected, or 99% of children are completely protected? I'm looking, but the CDC faq didn't make it clear.
I don't think that you can fractionalize immunity. You either are or you aren't, so it's the latter.
runes is offline  
#23 of 113 Old 02-23-2009, 09:33 PM
 
alegna's Avatar
 
Join Date: Jan 2003
Posts: 44,408
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by shuttlt View Post
Apologies for the storm of posts. I realized I'm confused about something:
"Most children who get the vaccine develop immunity to all three diseases (over 99% for measles and 95% for mumps and rubella). "
Does this mean most children are 99% protected, or 99% of children are completely protected? I'm looking, but the CDC faq didn't make it clear.
It means that 99%/95% are protected.

Those vaccines either confer immunity or not.

-Angela
alegna is offline  
#24 of 113 Old 02-23-2009, 09:34 PM
 
alegna's Avatar
 
Join Date: Jan 2003
Posts: 44,408
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by kidspiration View Post
I don't think that you can fractionalize immunity. You either are or you aren't, so it's the latter.
Actually, it seems on some vaxes/diseases you can. Pertussis for instance.

-Angela
alegna is offline  
#25 of 113 Old 02-23-2009, 09:43 PM - Thread Starter
 
shuttlt's Avatar
 
Join Date: Feb 2009
Posts: 516
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by kidspiration View Post
Yes. All 3 in the MMR...measles, mumps and rubella, are live virus vaccines.

As is varicella (chicken pox), rotovirus, oral polio and Flumist.
Interesting. Thanks.

Quote:
Originally Posted by kidspiration View Post
Shifting epidemiology occurs whether the vaccine program "reaches" herd immunity or not. Case in point...chicken pox.
You're right of course. Presumably the herd immunity idea would be to reduce the total number of cases past the point where the number of people impacted by shifting epidemiology matters.

Quote:
Originally Posted by kidspiration View Post
If you are asking if the key concepts of epidemiology can be boiled down to the math, and if this math is either correct or relevant, my original assertion still stands. It is a lot more complicated than a bunch of mathematical formulae.
I agree up to a point. On some level though this is about numbers. How many people get infected, how many die, how many are harmed. There may be too many significant variables to model, in which case, that would count as an 'answer' to my original post as far as I'm concerned.

Quote:
Originally Posted by kidspiration View Post
For example, how do they account for asymptomatic and subclinical cases? Certainly they won't figure in the math, and they won't count as a clinical "case" but it sure does factor into the epidemiology.
Why wouldn't they/couldn't they figure in the maths? If we know they exist then surely we can estimate their numbers?

Quote:
Originally Posted by kidspiration View Post
If you are planning to vax for the MMR, are you going to get titres drawn after vaccination and every year afterward to see if your child is immune? Why or why not?
That's a whole seperate thing. I don't pathelogically describe everything in my life with maths. The risk of my son being harmed by measles (or whatever) is very small, and would be far outweighed by the risk of him being psychologically damaged by my obsessing about his blood.
shuttlt is offline  
#26 of 113 Old 02-23-2009, 09:46 PM - Thread Starter
 
shuttlt's Avatar
 
Join Date: Feb 2009
Posts: 516
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks to everybody for clearing up the meaning of immunity for me.: It's an important word, and I was a little unsure of how it was being used in the context.
shuttlt is offline  
#27 of 113 Old 02-23-2009, 09:53 PM
 
tmaue's Avatar
 
Join Date: May 2007
Location: Peoria IL area
Posts: 134
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
In theory, with some vaccines, if they had the percentage of people needed for herd immunity vaccinated, and the vaccine worked for those people (which we know it doesn't in some people), then I could see it working. The problem with this is, as far as I have ever seen, their numbers are only accounting for young children who have gotten the vaccine. As we have seen in outbreaks of things like mumps, there are also adults who get the disease because they do not have immunity from the vaccine because it is pretty accepted that any protection you get from a vaccine wears off over time (which is why we have in recent years seen boosters added), and most adults are not running out to get revaccinated. So if you account for the middle age population and elderly who have not had the disease and then add in the adolescents who are starting to wear off, you are not going to get that percentage of the population being vaccinated for herd immunity to work. So, there really is no large vaccinated/immune herd that they would need to rely on herd immunity to work. There would be no good way for them to know what the true herd of our country is. Even if they did a study to test antibodies in a sample of the country, we know that antibodies do not tell use whether someone will actually get the disease or not, they would just be assuming who is part of the herd based on this info.

Then if you add in the fact that a vaccinated person can be a carrier of a disease and spread it to others, or they could come down with the disease from the vaccine, you make things even more complex and hard to pin down.

Then you have the interesting chickenpox virus which can come out as shingles later and continue to reinfect even if the virus was eliminated based on a vaccine. It is always going to rear its ugly head because you can even get shingles after being vaccinated for chickenpox.

Real herd immunity happens because the populations immunity doesn't wear off over time (I am speaking of live virus vaxes). This is how overtime disease decrease on their own and only the young are the ones getting the diseases.

With the bacterial type diseases, the bacteria will still be around and can be passed around even by the vaccinated, so really, the only herd is those who are vaccinated (which will wear off over time) or those who have been sick from the bacteria.

Anyway, to sum it up, you cannot gain herd immunity protection through vaccination unless the entire population is being vaxed at around the same time. We do not have that situation and likely never will since adults don't go for that sort of thing.
tmaue is offline  
#28 of 113 Old 02-23-2009, 10:07 PM
 
carriebft's Avatar
 
Join Date: Mar 2007
Posts: 6,947
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
One of the reasons this interests me so much is that most of the pro-vax position rests on herd immunity,
I have not read the rest of the thread yet but I wanted to comment that I feel that only the propaganda and the uneducated parts of the 'pro vaccination' world rely solely on herd immunity as an argument. If you really look deeper, I think there is usually agreement that some vaccines work to create herd immunity and benefit is gained from that while others do not (and there are a few that are argued about).

Although this distinction is lost when the propaganda starts.

"Parents are simply trustees; they do not own the bodies of their children"-Norm Cohen  Martial arts instructor intactlact.gifhomebirth.jpgnak.gif and mom to 4: DD1 (1/05) DS (7/06) DD2 (5/08) DD3 (2/11)
carriebft is offline  
#29 of 113 Old 02-23-2009, 10:10 PM - Thread Starter
 
shuttlt's Avatar
 
Join Date: Feb 2009
Posts: 516
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
@tmaue
Thanks for explaining that angle on herd immunity so succinctly.

Quote:
Originally Posted by tmaue View Post
In theory, with some vaccines, if they had the percentage of people needed for herd immunity vaccinated, and the vaccine worked for those people (which we know it doesn't in some people), then I could see it working. The problem with this is, as far as I have ever seen, their numbers are only accounting for young children who have gotten the vaccine. As we have seen in outbreaks of things like mumps, there are also adults who get the disease because they do not have immunity from the vaccine because it is pretty accepted that any protection you get from a vaccine wears off over time (which is why we have in recent years seen boosters added), and most adults are not running out to get revaccinated.
I must confess, when I started looking at the herd immunity that was exactly the problem I had. But (and sticking to measles) I then found the following information from our good friends the CDC.

If you're born prior to 1957 you've probably been exposed to epidemic measles, people vaccinated prior to 1968 needed boosters because they were vaccinated with innactivated measles, post '68 vaccination was with live measles and is believed to be lifelong.
http://www.cdc.gov/vaccines/vpd-vac/...-vac-risks.htm
shuttlt is offline  
#30 of 113 Old 02-23-2009, 10:11 PM
 
tmaue's Avatar
 
Join Date: May 2007
Location: Peoria IL area
Posts: 134
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by shuttlt View Post
People keep talking as if artifical immunity fades, but that isn't what the CDC says (as previously quoted):

Originally Posted by CDC
Most children who get the vaccine develop immunity to all three diseases (over 99% for measles and 95% for mumps and rubella). Protection is believed to be life-long.

If it's lifelong and 99% effective (in the case of measles), I don't see where there is much room for a natural immunity to do much better. Perhaps, how many children they mean by 'most' is where the difference lies?
The problem is looking you right in the face as to whether vaccine protection is life long. The CDC uses the words "believed to be" because it doesn't actually know but wants you to think it is life long because they say it is.

But what the CDC does know is that there are outbreaks all the time in completely vaccinated populations and nearly completely vaccinated populations. They have had to add the first booster for the MMR because they started to realize that the protection does indeed wear off. They are considering another booster for adolescents. If you look hard enough, you will find info were they know this is the case.

They also have admitted that the viruses mutate, such as they found out in the mumps outbreak a couple years ago. The would really like for adults to get some of these childhood vaccines such as the whooping cough one because they know that adults are not part of the herd and spread it around.

With natural immunity you do not have to worry about these things.

Even if 99% had antibodies for measles at time of injection (which is really where there numbers would be coming from), because of the wearing off, these same group of people would not still be at 99%.
tmaue is offline  
Reply

Quick Reply
Message:
Drag and Drop File Upload
Drag files here to attach!
Upload Progress: 0
Options

Register Now

In order to be able to post messages on the Mothering Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off