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Re: This study is misleading and was not scientifically worth doing
 

I note the conclusion of this study by Tozzi, Bisiacchi, Tarantino, De Mei, D'Elia, Chiarotti and Salmaso [1]. However, I also note the limitations of the study as described in the discussion:

'Some limitations should be considered in the interpretation of our results. The cumulative intake of thimerosal was relatively low, compared with that in other countries including the United States, where vaccination schedules included more thimerosal-containing vaccines in the first year of life. Moreover, there was no comparison group with no exposure to thimerosal, although our setting was appropriate to identify a dose response effect in the absence of any evidence suggesting a threshold dose for observation of an effect. Our analysis included only healthy children who were selected during enrollment in the original trial, and some families might have declined to participate in the present study because their children had cognitive developmental problems. This might have reduced the prevalence of adverse neuropsychological conditions and might have made potential differences hard to detect. The eligibility criteria of the original trial also limited the participation of low birth weight children, and only 55 children with birth weights of <2500 g underwent the neuropsychological evaluation (data not shown). Moreover, only 1% of children in this study received hepatitis B virus vaccine at birth. Although no effect of birth weight according to thimerosal intake was detected through multivariate analyses, our study was not powered to detect an association of thimerosal exposure and neuropsychological development in low birth weight infants.' [1]

I ask how it would be possible to draw any useful scientific conclusions from a study with such deficiencies in relation to the issues it purportedly set out to investigate? But I also reflect on the headline value of negative results for wider media consumption, as in the Associated Press report by Carla K Johnson, with contributions from Alberto Tozzi himself, Jennifer Pinto-Martin and Paul Offit [2] claiming this strengthens the evidence base for vaccine safety.

[1] Alberto Eugenio Tozzi, Patrizia Bisiacchi, Vincenza Tarantino, Barbara De Mei, Lidia D'Elia, Flavia Chiarotti, and Stefania Salmaso, 'Neuropsychological Performance 10 Years After Immunization in Infancy With Thimerosal-Containing Vaccines', Pediatrics 2009; 123: 475-482.

[2] Carla K Johnson, 'Study adds to evidence of vaccine safety', Associated Press, http://www.google.com/hostednews/ap/article/ALeqM5jp7ZD1RFVm7yOzgaB04Ra4dY_ZuQD95UKPPG0  

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