Real problems and uncertainties with vaccinations

[Ivor the Engineer]

I've started this thread so those with knowledge of vaccine development and/or medical use can tell us about the problems and uncertainties with vaccinations. For example:

How much Thirmosal is safe to inject into a human of a particular age and/or weight? How was this amount determined?

[paximperium]

Since Thimerosol is no longer used in vaccines used in infants I don't see the exact point but the best study is this:
http://www.cdc.gov/vaccinesafety/vsd/thimerosal_outcomes/

[Ivor the Engineer]

Since Thimerosol is no longer used in vaccines used in infants I don't see the exact point but the best study is this:
http://www.cdc.gov/vaccinesafety/vsd/thimerosal_outcomes/

Thanks for the link to the study. What I was after was something along the lines of this page:

http://www.ehponline.org/members/2002/suppl-1/11-23clarkson/clarkson-full.html

Abstract

The three modern "faces" of mercury are our perceptions of risk from the exposure of billions of people to methyl mercury in fish, mercury vapor from amalgam tooth fillings, and ethyl mercury in the form of thimerosal added as an antiseptic to widely used vaccines. In this article I review human exposure to and the toxicology of each of these three species of mercury. Mechanisms of action are discussed where possible. Key gaps in our current knowledge are identified from the points of view both of risk assessment and of mechanisms of action.

[Asolepius]

So if you already have the Clarkson paper why are you asking? Or do you want more like that to get a consensus?

[Deetee]

Bedtime reading:
http://www.nap.edu/catalog.php?record_id=9899#toc

Chapter on health effects (http://www.nap.edu/openbook.php?record_id=9899&page=147)


(Can you read it so I don't have to?) ;)

I don't really understood why it actually di take so long to phase out mercury from vaccines. It just never seemed to be considered a public health priority, and there were all those assurances that it caused no harm. Despite no evidence that it did cause harm, removal was correct on the precautionary principle, given that mercury may cause neurological damage in infants/fetuses. As has been expounded before, the decision to remove it was one that was agonised over (Smallwood) - The mercury militia would (and did) jump on this decision as an admission thimerosal did cause autism, and I can see why some were hesitant to advise it should be removed for these reasons, given the lack of evidence of harm stemming from its inclusion.
Multidose vials are also a bad idea anyhow - the potential risk for errors, contamination etc being real (albeit small). Why didn't people move to single dose vials earlier? I dunno. As to why thimerosal was originally chosen as a preservative? Not sure. perhaps the alternatives around at the time had even less going for them?

[Ivor the Engineer]

So if you already have the Clarkson paper why are you asking? Or do you want more like that to get a consensus?

Ideally I want sources on the ingredients of vaccines which could not be seen to have a potential bias toward minimising or ignoring risks associated with their use.

I'm also interested in hearing about how vaccines haven't worked as well as we would have like them to, or have lead to unforeseen negative consequences.

[Ivor the Engineer]

Thanks Deetee.

[Skeptiquette]

Hi Ivor,

I just recently read this paper, which I think is quite relevant to this thread. Here is the citation and abstract:

Heffernan JM, Keeling MJ. Implications of vaccination and waning immunity. Proc Biol Sci. 2009 Mar 4. [Epub ahead of print]

Abstract:
For infectious diseases where immunization can offer lifelong protection, a variety of simple models can be used to explain the utility of vaccination as a control method. However, for many diseases, immunity wanes over time and is subsequently enhanced (boosted) by asymptomatic encounters with the infection. The study of this type of epidemiological process requires a model formulation that can capture both the within-host dynamics of the pathogen and immune system as well as the associated population-level transmission dynamics. Here, we parametrize such a model for measles and show how vaccination can have a range of unexpected consequences as it reduces the natural boosting of immunity as well as reducing the number of naive susceptibles. In particular, we show that moderate waning times (40-80 years) and high levels of vaccination (greater than 70%) can induce large-scale oscillations with substantial numbers of symptomatic cases being generated at the peak. In addition, we predict that, after a long disease-free period, the introduction of infection will lead to far larger epidemics than that predicted by standard models. These results have clear implications for the long-term success of any vaccination campaign and highlight the need for a sound understanding of the immunological mechanisms of immunity and vaccination.

It is a pretty technical paper. And I don’t fully understand all the details, but the abstract gives a decent insight into the idea. This paragraph may also provide some insight:

Here we have considered the complex feedbacks between vaccination, waning immunity and boosting. In the absence of vaccination, lifelong immunity is maintained through frequent encounters with infection,
which act to boost the waning immune memory (this agrees with the findings of Whittle et al. 1999). However, when vaccination is introduced the prevalence of infection declines, which in turn reduces the amount of boosting
and hence the level of immunity (in agreement with Muller 2001). What is more surprising is that the interaction between vaccination and waning immunity can lead to pronounced epidemic cycles in which the
peak levels of infection can be of the orders of magnitude greater than the mean.

[Ivor the Engineer]

Thanks Skeptiquette.

I've read similar studies which dealt with chickenpox and the possible effect of mass vaccination increasing the age of infection and the incidence of shingles in adults who had chickenpox as children.

[kellyb]

Prevnar causing staph infections is an uncertainty/problem:

http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&uid=15183627&cmd=showdetailview&indexed=google

A trial with a 7-valent pneumococcal-conjugate vaccine in children with recurrent acute otitis media showed a shift in pneumococcal colonisation towards non-vaccine serotypes and an increase in Staphylococcus aureus-related acute otitis media after vaccination

These findings suggest a natural competition between colonisation with vaccine-type pneumococci and S aureus, which might explain the increase in S aureus-related otitis media after vaccination.



http://jama.ama-assn.org/cgi/content/abstract/292/6/716

Conclusions Streptococcus pneumoniae carriage, specifically of vaccine-type strains, is negatively associated with S aureus carriage in children. The implications of these findings in the pneumococcal vaccine era require further investigation


http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1482988

Whether the current increase in severe community-acquired S. aureus infections, including methicillin-resistant S. aureus (6), is partially caused by the recent introduction of the pneumococcal conjugate vaccine is yet to be determined

[Yuri Nalyssus]

I've started this thread so those with knowledge of vaccine development and/or medical use can tell us about the problems and uncertainties with vaccinations.
Here are a few references from my files -

http://www.bmj.com/cgi/content/full/320/7229/240 (http://www.bmj.com/cgi/content/full/320/7229/240)
http://www.cdc.gov/vaccines/recs/vac-admin/contraindications.htm (http://www.cdc.gov/vaccines/recs/vac-admin/contraindications.htm)
http://www.ncbi.nlm.nih.gov/pubmed/15917108?dopt=Abstract (http://www.ncbi.nlm.nih.gov/pubmed/15917108?dopt=Abstract)
http://www.bmj.com/cgi/content/extract/337/sep08_2/a1609?papetoc (http://www.bmj.com/cgi/content/extract/337/sep08_2/a1609?papetoc)
http://www.cdc.gov/vaccines/vac-gen/safety/default.htm (http://www.cdc.gov/vaccines/vac-gen/safety/default.htm)
http://www.bmj.com/cgi/content/full/328/7450/1220-b?etoc (http://www.bmj.com/cgi/content/full/328/7450/1220-b?etoc)
http://www.medscape.com/viewarticle/568534_1 (http://www.medscape.com/viewarticle/568534_1)

Yuri

[Capsid]

A rotavirus vaccine caused intussusception.
A respiratory syncitial virus vaccine enhanced disease.

The concern over the chicken pox vaccine has not occurred so far.

Forgot the Cutter incident (http://en.wikipedia.org/wiki/Cutter_Laboratories) that prompted use of an inactivated polio vaccine over the live version.

[kellyb]

The concern over the chicken pox vaccine has not occurred so far.



Which concern? There's this:

http://www.reuters.com/article/governmentFilingsNews/idUSN1429730720070314

And with fewer natural cases of the disease going around, unvaccinated children or children in whom the first dose of the vaccine fails to work have been catching the highly contagious disease later in life, when the risk of severe complications is greater, they said.

"If you're unvaccinated and you get it later in life, there's a 20-times greater risk of dying compared to a child, and a 10 to 15 times greater chance of getting hospitalized," said Jane Seward of the Centers for Disease Control and Prevention in Atlanta, who worked on the study.

While 73 percent of the youngsters who became ill in 1995 were under age 7, the rate dropped to 30 percent by 2004 because the children who got chickenpox tended to get it at an older age.

And when vaccinated children were infected, they tended to be sicker, probably because they were older.

[Miss_Kitt]

None of which changes the fact that the severity and frequency of lasting impacts of the diseases for which standard childhood vaccinations are recommended far outweighs the risks from the vaccines.

The paper arguing that a vaccinated population does not have regular encounters with pathogens to boost natural immunity against them did not--in the extracted portion, I have not yet read the full article--compare the infection rate and severity of a vaccinated population versus a largely unvaccinated population. Looking at the rate of death and disability from these diseases in developing world countries that lack vaccines is an eye-opener.

I am not familiar with the RSV vaccine Capsid mentioned, but I know the rotavirus vaccine was withdrawn when it was determined that it was causing intussusception in rare cases. A new rotavirus vaccine is now in trials, with the goal of reducing or eliminating that dangerous illness in babies.

--Miss Kitt

ETA: I'm old enough that I remember how these diseases used to be dealt with: We were all sent over to play at the house of the kid in the neighborhood who came down with the mumps (and later, chicken pox) so that we'd get it young. Then the moms rotated who was watching the sick kids while it burned through the neighborhood for a month or so. I was in older elementary school -- maybe 4th or 5th grade?--when the rubella vaccine was finally approved. We were all given it in the library at school (unless someone's family had religious issues), lined up like new recruits for the Army with one sleeve rolled up...there was a big public information campaign on that one, because rubella is not so dangerous for the person who has it, but it causes horrible birth defects in the infants of mothers who catch it while expecting.

It was just assumed that you would, by 10 or so, have gotten all of the following: "hard red" measles; "German measles" (rubella); chicken pox; and mumps. You got vaccinated against the often-lethal diseases: diphtheria, pertussis, tetanus, polio, and small pox. (Yep, I'm old enough to have been vaccinated against polio and also smallpox.) Even then, it was known that getting the SCDs (standard childhood diseases) younger was safer--but lacking a means of vaccination, the means of getting protection for later life was deliberate exposure at a young age.

I'll take vaccines, even with the side effects they sometimes have, over risking the rigours of the diseases.

[Deetee]

There are actually almost too many examples of vaccines being replaced by safer/more immunogenic products to list them all. You name it, it will have had problems, reactions, whatever.

I hardly think Ivor is a Generation Rescue mole compiling a list of horrible vaccine toxicities to trumpet to the Daily Mail (but one can never be 100% sure with him!)

[Deetee]

Hi Ivor,

I just recently read this paper, which I think is quite relevant to this thread. Here is the citation and abstract:
It is a pretty technical paper.

Hmm....
we parametrize
:confused:

[Skeptiquette]

what's the confused smiley for?
:confused:

[Ivor the Engineer]

There are actually almost too many examples of vaccines being replaced by safer/more immunogenic products to list them all. You name it, it will have had problems, reactions, whatever.

I hardly think Ivor is a Generation Rescue mole compiling a list of horrible vaccine toxicities to trumpet to the Daily Mail (but one can never be 100% sure with him!)

I am disheartened by your lack of trust Deetee.:D

I have an idea that if this info. was presented in the right way along with the benefits of vaccination, parents who are worried about having their children vaccinated would be able to use the rational parts of their brain to make the decision, which should hopefully get many more of them choosing to vaccinate (though perhaps not precisely to the CDC's schedule).

[Eos of the Eons]

http://www.paul-offit.com/

http://www.cdphe.state.co.us/dc/Immunization/vaccinesafety/Offitpiece.pdf



Methylmercury in the grain caused the hospitalization of 6,500 Iraqis and killed 450. Pregnant women also ate the bread and delivered babies with epilepsy and mental retardation. But they didn’t deliver babies with an increased risk of autism.


http://www.newsweek.com/id/165644

http://www.csicop.org/si/2007-06/novella.html

The amount of ethyl mercury in vaccines never exceeded the maximum recommended amount for methyl mercury, although it is safer than methyl mercury.
When the mercury containing preservative was still used, a child received up to only 1.9 µg/kg body weight per week when receiving vaccinations, which is well below the World Health Organization’s limit of 2.8 µg/kg per week. (That recommendation is for methylmercury, but the ethylmercury in thiomersal-containing vaccines is cleared by the body, and not accumulated the way methylmercury is. The half-life of ethylmercury is less than a week, and doesn’t compare to methylmercury’s 1.5 months.)

http://www.ncirs.usyd.edu.au/facts/thiomersal.pdf[

These values indicate levels of exposure that can be tolerated and have been deliberately calculated to be much lower than the level at which harm might occur. For example, the EPA level is 10 times below the lowest level calculated as causing harm, so there is a large built-in safety margin. In addition, these levels refer to methyl mercury, whereas thiomersal is converted to ethyl mercury, which is broken down and excreted more rapidly and does not accumulate in the body like methyl mercury

So, even if there was methyl mercury in the vaccines, it would have been below the harmful levels, but it's not even methyl mercury, it's ethyl mercury and that is not toxic to the body, and gets excreted far more quickly.

[Eos of the Eons]

I am disheartened by your lack of trust Deetee.:D

I have an idea that if this info. was presented in the right way along with the benefits of vaccination, parents who are worried about having their children vaccinated would be able to use the rational parts of their brain to make the decision, which should hopefully get many more of them choosing to vaccinate (though perhaps not precisely to the CDC's schedule).
These kind of facts sheets are available, along with ones that show the risk from disease compared to risks from vaccines.
http://www.cispimmunize.org/fam/Compare%20the%20Risks.pdf

I think I'd take a risk of an ear infection (which my kids never got after being vaccinated) over the risks associated with the diseases that vaccines prevent.

[Eos of the Eons]

Now. Let's look at overblown antivaxxer claims:

They say that vaccines cause autism, reduced IQs, more rates of illness (from so-called overwhelmed immune systems), cause every disease under the sun-including diabetes and asthma, etc.

http://www.mothering.com/discussions/showthread.php?t=864692

http://www.mothering.com/discussions/showthread.php?t=991668


Novella tries to address this, but nobody from those forums are going to listen to him:
http://www.sciencebasedmedicine.org/?p=9
http://www.theness.com/neurologicablog/?p=308

[kellyb]

Here's another uncertainty:
http://www.medscape.com/viewarticle/572891

[Yuri Nalyssus]

I have an idea that if this info. was presented in the right way along with the benefits of vaccination, parents who are worried about having their children vaccinated would be able to use the rational parts of their brain to make the decision, which should hopefully get many more of them choosing to vaccinate (though perhaps not precisely to the CDC's schedule).
Well the NHS have a 'draw up a personalised immunisation schedule' (http://www.immunisation.nhs.uk/) page as well as a lot of good information about risks and benefits and the science behind vaccines, details of how they're produced etc.

Any site giving an honest appraisal of vaccine risks should include a mention that the situation is constantly under review and as problems become apparent they are being dealt with - more than can be said of any cam practices (especially nosodes in this case) for which there are no checks and balances and whose practitioners go into denial quicker than a sea anemone at low tide if questioned about efficacy, safety or any other reductionist details like that.

Yuri

[Leviath]

Unfortunately the anti-vaxx propaganda is starting to emerge here in Norway (we've been mostly spared so far) so this thread looks promising for references. I have read some of our local nut-cases' propaganda and I do see how they mix in problems we know existed with some out-of-date vaccines with their current imaginary connections to autism and diseases. It's the good old argument "it was harmful 20 years ago, hence it is harmful now too".

I also want to add to this thread that I read somewhere (can't remember where and I can't link yet anyway) that research is being done to replace aluminium in vaccines. Not because it is thought to be harmful, but because more effective subtances are believed to exist. From what I recall aluminium works as some kind of catalyst or "booster" for the vaccines.

[LarianLeQuella]

The only people who make the claim that vaccines should be 100% safe and effective are the anti-vaxxer (pro-disease) nuts... The problems assoiciated with vaccines are NOT autism, but there are cases of adverse reactions, infections, and the like. However, the risk of these problems are deemed acceptable compared to the diseases they prevent. As is the case in pretty much ALL of medicine and even your every day life (the risk of dying in a car crash is outweighed by your desire to get somewhere quicker, etc.).

[Deetee]

what's the confused smiley for?
:confused:

To indicate my incomprehension of the "english" language, .....and my despair.

(Not at you, but the reference)

[Deetee]

Bedtime reading:
http://www.nap.edu/catalog.php?record_id=9899#toc

Chapter on health effects (http://www.nap.edu/openbook.php?record_id=9899&page=147)


(Can you read it so I don't have to?) ;)

I don't really understood why it actually di take so long to phase out mercury from vaccines. It just never seemed to be considered a public health priority, and there were all those assurances that it caused no harm. Despite no evidence that it did cause harm, removal was correct on the precautionary principle, given that mercury may cause neurological damage in infants/fetuses. As has been expounded before, the decision to remove it was one that was agonised over (Smallwood) Simpsonwood - The mercury militia would (and did) jump on this decision as an admission thimerosal did cause autism, and I can see why some were hesitant to advise it should be removed for these reasons, given the lack of evidence of harm stemming from its inclusion.
Multidose vials are also a bad idea anyhow - the potential risk for errors, contamination etc being real (albeit small). Why didn't people move to single dose vials earlier? I dunno. As to why thimerosal was originally chosen as a preservative? Not sure. perhaps the alternatives around at the time had even less going for them?

Correction as above.
It felt so wrong, it felt so right.... when I typed it.
Smallwood was the Prince of Wales' report into integrative medicine.
Simpsonwood was the one I meant - the CDC meeting on vaccines and autism.

[Deetee]

Here's another uncertainty:
http://www.medscape.com/viewarticle/572891

Retrospective study in Canada indicating delaying whole pertussis vaccine (DTP) reduced the incidence of asthma.
Limitations of this study include possible ascertainment bias; findings not yet confirmed with the DaPT vaccine; and inability to refute the issue of early-life infections as an explanation for the association between delayed immunization and protection against the development of asthma.
Important points.
We don't know if this applies to the DTaP vaccine used currently.
We don't know if the reasons DTP was delayed in the children was a confounder - the vaccines may have been deferred because the children had a coincidental infection, and infections themselves appear to reduce the incidence of asthma.

[Capsid]

Which concern? There's this:

http://www.reuters.com/article/governmentFilingsNews/idUSN1429730720070314Ok thanks. I'd read elsewhere that this wasn't occurring. Just goes to show you need to read around.

[Ivor the Engineer]

<snip>

So, even if there was methyl mercury in the vaccines, it would have been below the harmful levels, but it's not even methyl mercury, it's ethyl mercury and that is not toxic to the body, and gets excreted far more quickly.

Ethyl mercury is toxic to the body, though almost certainly not in the doses (previously) received from vaccinations.

[Yuri Nalyssus]

From what I recall aluminium works as some kind of catalyst or "booster" for the vaccines.
The term is adjuvant.

Yuri

[Ivor the Engineer]

Well the NHS have a 'draw up a personalised immunisation schedule' (http://www.immunisation.nhs.uk/) page as well as a lot of good information about risks and benefits and the science behind vaccines, details of how they're produced etc.

I had a look at the NHS immunisation site over the weekend and was quite impressed with it, mainly because it didn't appear to be spinning the facts to try to get parents to have their children vaccinated.

Any site giving an honest appraisal of vaccine risks should include a mention that the situation is constantly under review and as problems become apparent they are being dealt with - more than can be said of any cam practices (especially nosodes in this case) for which there are no checks and balances and whose practitioners go into denial quicker than a sea anemone at low tide if questioned about efficacy, safety or any other reductionist details like that.

Yuri

I agree. I think explaining the prisoner's dilemma parents face with respect to some vaccinations might also be worthwhile.

[Ivor the Engineer]

The term is adjuvant.

Yuri

IIRC, no one knows quite how they work either.:)

[Yuri Nalyssus]

IIRC, no one knows quite how they work either.:)
cough... the term is adjuvant. I 'spec they boost the immune system. :o

Yuri

[Leviath]

The term is adjuvant.

Yuri

Thank you. Here's a little bit about it (replace the xx with tt):
hxxp://www3.interscience.wiley.com/journal/118783452/abstract?CRETRY=1&SRETRY=0

Does anyone know more about this allegded link between aluminium in vaccines and alzheimer?

[Eos of the Eons]

We encounter the minerals (aluminum salts) used in vaccines every day because they occur naturally in our food and water. They are safely used as ingredients in cake mixes, deodorant, antiperspirant, and other every day items:
"Aluminum (http://www.immunizationinfo.org/vaccine_components_detail.cfv?id=61) is a very abundant element in our environment. It is in many foods we eat, many personal hygiene products we apply to our skin (deodorants, for example), and many medicines we ingest. Thus, all infants are exposed to aluminum in the environment. Breast milk, for example, contains approximately 40 micrograms of aluminum per litre, and infant formulas contain an average of approximately 225 micrograms of aluminum per litre."

Even people trying to go "all natural" for their food sources still get the same doses of these minerals in their "natural" food and water sources. Aluminum (http://www.eoearth.org/article/Aluminum) and other minerals are a natural part of our world. Even water can kill us if we drink too much of it at once. Water is also a chemical. The claims that vaccines are poisonous are simply not true. People can say the same about the water, but you have to drink far more water than could ever be used in vaccines before it will kill you (http://www.msnbc.msn.com/id/16614865/).


http://www.stopjenny.com/VaccineInformation.html

No, the aluminum in vaccines doesn't cause Alzheimers.

[Eos of the Eons]

Ethyl mercury is toxic to the body, though almost certainly not in the doses (previously) received from vaccinations.

Actually it's not. It's in a form the body doesn't process, it is just elimated. To be toxic the body must be affected by it, usually by attempting to utilize it, store, etc. It's like you're trying to say Splenda could be like sugar to the body, but it is in a form that the body just excretes it.

Would recommend a chemistry course. Even formaldehyde is broken down before it is toxic to the body.

[Eos of the Eons]

I had a look at the NHS immunisation site over the weekend and was quite impressed with it, mainly because it didn't appear to be spinning the facts to try to get parents to have their children vaccinated.



I agree. I think explaining the prisoner's dilemma parents face with respect to some vaccinations might also be worthwhile.
Spin? Do tell.

Prisoner's dilemma. Do tell on that as well.

[Ivor the Engineer]

Actually it's not. It's in a form the body doesn't process, it is just elimated. To be toxic the body must be affected by it, usually by attempting to utilize it, store, etc. It's like you're trying to say Splenda could be like sugar to the body, but it is in a form that the body just excretes it.

Would recommend a chemistry course. Even formaldehyde is broken down before it is toxic to the body.

So this is wrong? (from my first link):

Ethyl mercury in the form of thimerosal has found wide application in medicine as a disinfectant. Axton (54) reported case histories of four children and two adults severely poisoned by accidental exposure. Five of the six cases died. Rohyans et al. (55) reported a case of severe poisoning from treatment of an infected ear. Pfab et al. (56) reported on an attempted suicide from drinking a solution of thimerosal, resulting in severe poisoning. Treatment of infants with omphaloceles resulted in high levels of mercury in autopsy tissues (57). Cases of human poisoning have also occurred from infusion of large volumes of plasma containing thimerosal as a preservative (58,59).

[JoeTheJuggler]

I don't think it's been mentioned yet, but there are known allergies to some of the ingredients in some vaccinations.

ETA: Not much of a problem when the allergy is known:
http://www.sciencedaily.com/releases/2008/09/080902074557.htm

[JoeTheJuggler]

Prisoner's dilemma. Do tell on that as well.

Your kid could benefit from the public health benefits of most kids getting their shots even if your kid doesn't. (In other words, your kid could avoid the relatively small risks while still enjoying a large part of the benefit of vaccinations.) Of course, if the other "players" all adopted that strategy, it wouldn't work.

[Ivor the Engineer]

Spin? Do tell.

Emphasizing the positives while presenting the negatives in a form which is difficult to understand.

Prisoner's dilemma. Do tell on that as well.

For many diseases, if enough people around me are vaccinated, the risk from being vaccinated is greater than not being vaccinated*, so it makes sense to refuse to be vaccinated (defect in prisoner's dilemma speak). But if everyone refused the vaccination then the risk from the disease would be greater than those from being vaccinated, so it then makes sense to choose to be vaccinated (cooperate).




*Because as more people are vaccinated the chances of an individual contracting the disease, irrespective of vaccination status go down.

[kellyb]

Another uncertainty:

http://www.columbia.edu/cu/news/clips/2007/11/27/ATheoryWASHINGTONPOST.pdf

Studies show the increased risk of schizophrenia appears linked to maternal infections during the first and second trimesters of pregnancy -- especially flu infections. Since the flu peaks in the fall, this might explain why babies born in the winter and spring have the higher risk.

But if research into the links between early maternal infections and schizophrenia might one day provide researchers with clues about how to attack the disease before symptoms become apparent, it also raises difficult public health conundrums.
That's because the newest studies suggest the culprit may not be infections such as the flu per se, but pregnant mothers' immune reactions to such infections. Current guidelines recommend that pregnant women get a flu shot -- and the point of the flu vaccine is to set off an immune reaction. If the risk for schizophrenia is increased as a result of maternal antibodies, might protecting mom and baby from the flu raise the risk the child could get schizophrenia years down the road?

"Obviously, the safe thing to do is to go with the experts, and the experts are the CDC," said Paul Patterson, a professor of biology at the California Institute of Technology and one of the leading researchers into the link between maternal infections and schizophrenia. "However, if it was my wife, I would not [want] her vaccinated."

[jdp]

Just out of curiosity what is the level of efficiency of most vaccinations? What level of effect is considered acceptable to move forward on clinical testing or onto approval? I suspect that in most cases it is pretty high, >60% but in certain specific cases lower may be acceptable.