or Connect
Mothering › Mothering Forums › Baby › Baby Health › Vaccinations › Another herd immunity thread
New Posts  All Forums:Forum Nav:

Another herd immunity thread - Page 2

post #21 of 113
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.
post #22 of 113
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.
post #23 of 113
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
post #24 of 113
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
post #25 of 113
Thread Starter 
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.
post #26 of 113
Thread Starter 
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.
post #27 of 113
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.
post #28 of 113
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.
post #29 of 113
Thread Starter 
@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
post #30 of 113
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%.
post #31 of 113
They did not go with another MMR because of waning immunity. They went with a second MMR to get immunity levels higher in the first place. So MMR 1 makes 90-95% immune and MMR 2 makes 95-99% immune depending on which numbers you believe.
post #32 of 113
Quote:
Originally Posted by shuttlt View Post
@tmaue
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
This mainly just applies to the older population but does not apply to my generation. I have not had the MMR in 30 years nor have I had these diseases (and very few people in my age group ever had these, at least I didn't know anyone personally who did), so the chances of me not getting one of these diseases if I was exposed, would be very low. I do not consider myself or those my age (early 30's) to be part of the herd. So in other words, there is still a large part of the population who falls into the category of having iffy protection.
post #33 of 113
where is the evidence of the iffy measles protection? you mean from people who have been neither immunized or exposed?
post #34 of 113
Thread Starter 
Quote:
Originally Posted by carriebft View Post
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.
The moral thrust of it relies more than a little on herd immunity though, doesn't it? I mean, remove herd immunity and it really is just about individual choice. There would still be a point to vaccines, but a lot of the will to fight would go out of the pro-vax camp, I think.....

Quote:
Originally Posted by carriebft View Post
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).
That is very definately not the impression I had gotten from a number of the posters on the forum.

Quote:
Originally Posted by carriebft View Post
Although this distinction is lost when the propaganda starts.
That certainly happens, but I really had the impression that a significant people believed herd immunity didn't happened and in any case vaccines don't work.
post #35 of 113
Quote:
Originally Posted by carriebft View Post
They did not go with another MMR because of waning immunity. They went with a second MMR to get immunity levels higher in the first place. So MMR 1 makes 90-95% immune and MMR 2 makes 95-99% immune depending on which numbers you believe.
Not from what I remember reading, though I am just going from memory and don't feel like looking it up right now. They should have had that info from the beginning and should have known to have a booster, but they did not have a booster. Same with chickenpox. Once they see that it is not providing protection, you add a booster. They could easily tell you they are adding a booster to up antibodies, but that doesn't mean it is true.

Again, they should have had the numbers all along and would have known they needed a booster, instead of waiting years to do it. Without looking, I don't know the time frame between when they started the MMR and when they added the booster.
post #36 of 113
I meant agreement in the so-called 'provaccination' camp-- ie, those in science and medicine who speak openly for vaccination. There seems to actually be an understanding that not all vaccines work for herd immunity there, but they use the herd immunity argument to sell vaccines to the masses.
post #37 of 113
Thread Starter 
Quote:
Originally Posted by tmaue View Post
This mainly just applies to the older population but does not apply to my generation. I have not had the MMR in 30 years nor have I had these diseases (and very few people in my age group ever had these, at least I didn't know anyone personally who did), so the chances of me not getting one of these diseases if I was exposed, would be very low. I do not consider myself or those my age (early 30's) to be part of the herd. So in other words, there is still a large part of the population who falls into the category of having iffy protection.
You would presumably have had the live measles vaccine and, at least according to the CDC, should have lifelong immunity.
post #38 of 113
Quote:
Originally Posted by tmaue View Post
Not from what I remember reading, though I am just going from memory and don't feel like looking it up right now. They should have had that info from the beginning and should have known to have a booster, but they did not have a booster. Same with chickenpox. Once they see that it is not providing protection, you add a booster. They could easily tell you they are adding a booster to up antibodies, but that doesn't mean it is true.

Again, they should have had the numbers all along and would have known they needed a booster, instead of waiting years to do it. Without looking, I don't know the time frame between when they started the MMR and when they added the booster.
I believe you are wrong here. but I would be willing to look at evidence supporting the idea of waning immunity leading to another vaccine.
post #39 of 113
Another assumption about vaccines that bothers me, besides vaccine=immune, is that artificially induced herd immunity is inherently desirable. When we look at measles the answer for me is no. Measles and humans have successfully coexisted for a long time in balance. Are there unintended consequences of our attempt to control the balance?

I know that's a little more philosophical than the math question but I do feel that the math is based on two (or more) assumptions:

1. vaccine = immunity
2. herd immunity is desirable with x disease.
post #40 of 113
Quote:
Originally Posted by carriebft View Post
I believe you are wrong here. but I would be willing to look at evidence supporting the idea of waning immunity leading to another vaccine.
Well with varicella, for example, not only are they adding boosters but they have to develop a shingles vaccine to deal with the diminished immunity in adults.
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Vaccinations
Mothering › Mothering Forums › Baby › Baby Health › Vaccinations › Another herd immunity thread