Correlation and causation - Page 11

[an_domhan]

Originally Posted by carriebft

We know the vaccine played a role in the reduction of polio because we have the connection and the mechanism for that connection.

Please explain the mechanism. TIA

[carriebft]

your first post: what information are you looking for? what would this evidence look like to you? I can try and provide once I know what it is you are looking for. I admit I am not quite sure.

your second post: You might want to read up on this specific vaccine- I think maybe that might help you understand how it was tested. Also, there are many vaccine studies with placebo controls- saline placebo at that. I can start a new thread if you want examples. on your second paragraph: I am not sure where that came from. I would not say those things. I also support choice in vaccination.

Your third post: again, you want information on how vaccines create immunity? do you mean something along the lines of an explanation of what happens once the vaccine is given and lymph takes over? or how immunity can prevent disease? this are pretty broad and in depth topics. maybe we should start a new thread on them!

[Scattershoot]

Originally Posted by carriebft

Also, there are many vaccine studies with placebo controls- saline placebo at that. !

I am interested in these studies. I admittedly have not looked at all that many studies in the past few years. I kind of got burned out. I can't ever recall one study that used a true placebo that I had looked at. They would mention placebo, but it had something in it, such as aluminum. If you have easy access to these (I know how time consuming it is to go back and post research), I'd be interested in reading these.

[an_domhan]

Originally Posted by carriebft

your first post: what information are you looking for? what would this evidence look like to you? I can try and provide once I know what it is you are looking for. I admit I am not quite sure.

? You've repeated stated that the mechanism for which vaccines have been proven to "work" has been demonstrated.

I'm familiar with this vaccine. I'm also familiar with how the stroke of a pen reduced incidence of this disease overnight.

Please post studies (any vaccine will do) with bona-fide control groups.... don't forget the exclusion criteria.

[an_domhan]

Originally Posted by Scattershoot

I kind of got burned out. I can't ever recall one study that used a true placebo that I had looked at. They would mention placebo, but it had something in it, such as aluminum.

Or, those in the control group were already vaccinated.... Comparing people vaccinated with X against people vaccinated with Y.... and so on.

[an_domhan]

Originally Posted by carriebft

Your third post: again, you want information on how vaccines create immunity? do you mean something along the lines of an explanation of what happens once the vaccine is given and lymph takes over? or how immunity can prevent disease? this are pretty broad and in depth topics. maybe we should start a new thread on them!

It's very likely they've been discussed ad nausem here. I wouldn't know, I don't come here that often unless I need a dose of hostility. (Not that you're hostile, this topic makes me that way)

Immunity is a relative term depending on how robust the host is. There is also no accurate way to control for variables in the real world. I'm sorry you're not following what I previously posted (seriopositivity), let me try again:

Before vaccines enter the clinical trial circus for human use, they undergo animal testing. When animals are presented with the disease causing agent, "immunity" is measured when the animal ceases to exhibit symptoms to said agent. A person that does not exhibit symptoms, is not a person that is immune (a definition riddled with holes). It is a person that is simply not presenting in the same fashion as one would if they had never been challenged. And they are definitely off the radar as a person that might be asymptomatically, and quietly, spreading disease among the herd. Should an unvaccinated person come into contact with them, the unvaccinated is very likely to present with classic symptoms and go on to be clinically diagnosed based on both symptomology and their vaccination status.

Dealing with and overcoming disease also creates immunity. Vaccines are not the only method of disease prevention.

[ema-adama]

Originally Posted by carriebft

The Cutter Incident touches on it but more is in Vaccinated: One Man's...

you said:

I am saying that there is no more to the claim that the Salk vaccine single handedly reduced polio incidence in the 1950's in the USA than a graph.

You are saying that the only evidence that exists for this vaccine's effectiveness is a graph.

Not the trials, the field trials, the science behind vaccination with (more fault on wording before, sorry) inactived virus/particles, etc.....a graph.

though we may know more about how the immune system responds to the inactived vaccine NOW, that doesn't change how it worked THEN-- it's still the same principles.

I want to respond to the IPV of then and the IPV of now. From what I have understood the IPV has been dramatically improved on since 1955. It is definitely not the same vaccine in use. The idea of mounting an immune response by introducing a killed virus is still pretty much the same. The vaccine itself not so much. It is impossible to compare todays' IPV with the IPV available in the USA in the 1950's.

Originally Posted by carriebft

Although, if you are placeing your emphasis on the words "single handedly" then maybe I am arguing a different point than you are.

I am saying:
We know the vaccine played a role in the reduction of polio because we have the connection and the mechanism for that connection. We know how the vaccine works, how it creates immunity and the results of that immunity in the subjects it was tested/used in (and all the science that goes along with that). Then we have more evidence in the reduction of polio (ie, "the graph"). If someone says the graph is the sole reason for their belief, then, yes, they are being narrow minded about the subject. One needs to find the mechanism of the correlation to create the causation. The mechanism is found in how the vaccine works to create immunity.


BTW: the oral vaccine is the one that prevents multiplication of the virus in the gut, so obviously research on IPV will not show such an effect.

The key to my question does lie in the phrase 'single handedly'.

The Salk vaccine was not consistently translating into protection from polio. And there was/is a fair amount of controversy about how to inactivate the polio viruses. Salk had his opinion, and other scientists had their opinions. This study from Sweden looks at why the Salk vaccine might have been experiencing problems when it came to causing polio. The study is from 1957.
http://www.pubmedcentral.nih.gov/pag...23&pageindex=1

It appears Salk assumed formalin would inactivate the virus according to the methodology he was using, while there is evidence that this was not the case.

Back to the graph. Yes, 'narrow minded' would describe the people I know who like to use the graph as evidence. So, I am curious as to how someone can establish what impact the Salk vaccine had on the decline in incidence. Two confounding variables that interest me is a) the reclassication of polio the disease. If the disease had not been reclassified, would we still see such dramatic numbers post Salk vaccine? and b) the removal of DDT from public use. If DDT continued to be in use, would we have seen such a dramatic decrease in polio with the Salk vaccine? I think these are reasonable questions to ask. And to the best of my knowledge, there is no way to actually get an answer.

I think it is worth noting that inherent to my question is the possibility that the Salk vaccine may have worked for some people and that it might have played some role in the reduction of incidence in polio. My concern is that there are other important variables that have the potential to seriously impact on the numbers. I do not think that such a dramatic graph can be attributed to the Salk vaccine alone.

The comments I quoted from the study on gut immunity following IPV were following this:

Some comment should be made concerning the antibody levels observed in the sera of vaccinated children. It will be recalled that the sera for antibody determination were obtained in the late summer and, in most instances, the vaccine had been administered the previous spring. Our failure to find any clear-cut differences between the vaccinated and unvaccinated children either in regard to the presence of antibody or level of antibody is somewhat disturbing.

If the findings of our study indicate the true situation, it might well be asked why the incidence of poliomyelitis in the United States has fallen so dramatically within the past two years, coincident with the introduction of the vaccine. Amoung the significant number of persons not yet immunized cases should occur if vaccination has not reduced the opportunity for exposure.

http://www.pubmedcentral.nih.gov/pag...8&pageindex=10

[Scattershoot]

Originally Posted by an_domhan

Or, those in the control group were already vaccinated.... Comparing people vaccinated with X against people vaccinated with Y.... and so on.

Very true.

[bbrandonsmom]

Ema-I found this just now, has to do w/ the first IPV I guess and not after they changed it. It might be the reason they did change it? I'm not up to par on my polio facts.
http://www.iom.edu/?id=6014

[ema-adama]

This link is taking me to the IOM homepage. I didn't see anything specific to polio?

I am still learning about the IPV from 1955. It really is facinating to understand more about it all. I used to think that tonsillectomy was a bit of a red herring when it came to understanding polio in the 1940's and 50's. I also used to think that DDT and reclassification of the disease were intended to distract questioning parents from the truth that the vaccine saved us. I cannot say with any certainty that the vaccine hype is just a myth, but neither can I say with any certainty that the IPV of 1955 really did achieve all that has been claimed.

A 92% decrease in incidence of polio is a mighty claim, and so far I am not findng the evidence that the Salk vaccine did indeed do that. In fact I am finding evidence that brings this claim very much into question. At least questionong the role of the vaccine in single handedly reducing polio so dramatically.

The knowledge and resources scientists had at their disposal in the 1950's was remarkably reduced compared to today. The science may have been good for it's day (or not if Salk was not actually using formalin effectively). But the argument that it was all scientificaaly sound is not really relevant. Jenner was also considered to be scientifically sound in his day. The first live measles vaccine was also scientifically sound, the Edmonston B strain. And yet it was so virulent, that it was removed from use and replaced with further attenuated strains. Just because the science of the day supports something, does not mean that it holds true forever. Or cannot be improved upon.

That graph is very problematic.

[bbrandonsmom]

Ok, didn't know it did that. In the search box type in "simian", and the link will pop up. Research on the connection between the first IPV? (since the one they are talking about was pulled about 1950-60) and cancer.

[caned & able]

ema-adama: Salk was not appreciated by his peers when he worked in Pittsburgh, PA. He was never nominated for a Nobel Prize and he left to live in N. California as soon as he could. None of his co-workers followed him. There was some disagreement there that was never disclosed.

[ema-adama]

Originally Posted by bbrandonsmom

Ok, didn't know it did that. In the search box type in "simian", and the link will pop up. Research on the connection between the first IPV? (since the one they are talking about was pulled about 1950-60) and cancer.

http://www.mothering.com/discussions...d.php?t=294017

For a great discussion on contamination of vaccines.

Originally Posted by caned & able

ema-adama: Salk was not appreciated by his peers when he worked in Pittsburgh, PA. He was never nominated for a Nobel Prize and he left to live in N. California as soon as he could. None of his co-workers followed him. There was some disagreement there that was never disclosed.

Yes, I reckon something happened that is not not being openly discussed. And it looks like it could have had something to do with his personality and also with his methedology of inactivating the polio virus with formalin. There was scientific debate over how to do it, and it looks like there is evidence that the methedology that Salk was using was not effective.

What I find strange is that people that do believe that the Salk vaccine did what it is claimed to have done, do not have the evidence that that vaccine did it.

I am dissapointed that the questioning of the Salk vaccine is considered irrelevant.

In a discussion where vaccines are being questioned, parents are asked to support their questions with evidence. It strikes me that the scientific community is not pressed to offer their evidence for such a an amazing claim.

[bbrandonsmom]

Thanks for the link Ema.

[ema-adama]

No problem. I noticed that the FDA link on polio vaccine contamination is no longer active. I'll have to see if I saved the document itself.