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I disagree with vaccineinduced 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 reexposed to it through their own children and grandchildren for natural boosters. That is the herd immunity.

The provax 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),



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. 
Herd Immunity:
if individual immunity = or > critical mass then pathogen can not propagate ergo natural herd immunity. is different than what provax claims: if # of vaccinated individuals = or > critical mass then pathogen can not propogate 
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 lifelong.

This is missing a big variable: level of acquired immunity per individual.

Sadly, wikipedia's entry on herd immunity does not even discuss the natural biologic process of herd immunity but only the theory of vaccineinduced herd immunity (in fact, it is hard to find information on herd immunity in a nonvaccine light anywhere online). The mix up (intentional or not) of vaccine and immune is a huge part of the divide between pro and antivax people IMO.

The problem as PaigeC pointed out very clearly is the assumption that vaccineinduced "immunity" is the same as natural immunity.

That is the first assumption that the rest of the argument is based on. This is false.

It is fundamentally flawed to talk about herd immunity as a concept that is removed from specific vaccines/diseases.

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:

The maths, as I understand it is what the provax 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.

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 lifelong.

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 reexposed to it through their own children and grandchildren for natural boosters. That is the herd immunity.

Sure, that is an acknowledged problem with vaccination programs that fail to reach herd immunity. I don't think that is disputed.

The maths, as I understand it is what the provax 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.

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. 
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. 
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. 
Yes. All 3 in the MMR...measles, mumps and rubella, are live virus vaccines.
As is varicella (chicken pox), rotovirus, oral polio and Flumist. 
Shifting epidemiology occurs whether the vaccine program "reaches" herd immunity or not. Case in point...chicken pox.

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.

One of the reasons this interests me so much is that most of the provax position rests on herd immunity, 
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.

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 lifelong. 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? 

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