Tuesday, December 27, 2011

Vaccines and Pregnancy: Lack of randomized, placebo-controlled trials and ... means ...?

My children have received their recommended vaccinations. I have had some although I am old enough that I received my measles and mumps shots the old fashioned way ... I had bad cases of both mumps and measles as a child.  I have not ... as yet ... attributed my son's autistic disorder to any injections he received, or that his mother received while carrying him, although I keep an open mind on the subject. I refuse to simply accept either  camp's dogmatic conclusions.

I believe that the public health authorities have shot themselves, no pun intended, in the foot with their dogmatic assertions that vaccines have "debunked" any vaccine autism connection and with their condescending, and at times pejorative and nasty, dismissal of parental observation, also known as direct, first hand observation, of changes in their children's conditions immediately following vaccinations. 

As one who has advocated strenuously for evidence based ABA treatment for autistic children I marvel at the ease with which some in the health sciences still do not accept ABA as an effective autism intervention after decades and hundreds of studies yet turn around and claim that a couple of dozen studies debunk all possible vaccine and vaccine ingredients even those given to pregnant women as possible causes or triggers of autism disorders.  I am amazed that some of the same people who claim that we can not know whether autism increases are real because of changed diagnostic definitions and social factors turn around and claim that epidemiological studies which fail to find a vaccine autism connection in some circumstances proves for all time that all possible vaccine autism connections have been dis-proven while ignoring for those purposes the changed diagnostic definitions and social awareness factors that complicated drawing safe conclusions.

Then there is the occasional study which does not seem to receive the usual attention of the NYT, the LAT or CNN perhaps because they are not so dogmatic in the debunking claims. The following abstract does not specifically mention autism disorders, (it might not get published if it did) but makes some interesting observations relative to the vaccine autism wars:

Authors: Makris, Marinos C.; Polyzos, Konstantinos A.; Mavros, Michael N.; Athanasiou, Stavros; Rafailidis, Petros I.; Falagas, Matthew E.
Source: Drug Safety, Volume 35, Number 1, 1 January 2012 , pp. 1-14(14)


Immunization during pregnancy has the potential to protect the mother and the newborn from preventable diseases. Current recommendations suggest that inactivated vaccines might be considered during pregnancy when the benefits outweigh the risks.

In this review, we aimed to evaluate the safety of hepatitis B (HB) vaccine, pneumococcal polysaccharide vaccine (PPSV) and meningococcal polysaccharide vaccine (MPSV) administration during pregnancy by systematically reviewing the available evidence in PubMed and Scopus databases, as well as postmarketing surveillance data (including the Vaccine Adverse Event Reporting System [VAERS] database). A total of 18 studies were eligible for inclusion in the review. Six studies provided data on HB vaccine, six on PPSV and three on MPSV; three additional studies compared PPSV with MPSV. Additionally, 91 reports on vaccinations of pregnant women were identified from postmarketing surveillance data (88 on HB vaccine, 2 on PPSV, 1 on MPSV). The most common complaints were local reactions, including tenderness and swelling. Overall, immunization during pregnancy did not seem to be associated with a teratogenic effect on the fetus, preterm labour or spontaneous abortion. However, the lack of randomized, placebo-controlled trials, or even large cohort studies, in addition to the inherent limitations of the reviewed observational studies with small statistical power, precluded safe conclusions. Large, prospective, population-based cohort studies are needed to elucidate this issue. (bold emphasis added -HLD)

The bold highlighted text states clearly that, at least for the vaccines listed in the study report title safe conclusions could not be drawn about the safety of those vaccines when given to pregnant women ... because of the lack of randomized, placebo-controlled trials, or even large cohort studies, in addition to the inherent limitations of the reviewed observational studies with small statistical power.  


Ruby Claire said...
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Kathy in Colorado said...

Well said - I've personally experienced that "first-hand observation" you wrote of, but try to avoid a dogmatic stance (what I call "frothing at the mouth") diligently. We need science. Unbiased science, with the primary goal of ensuring the safety of our kids both today and for generations to come. I fear we will be remembered by historians as the generation that created thousands upon thousands of people with autism via denial and dedication to the almighty pharmaceutical buck.