Validity of "studies" purporting to vindicate vaccination

An Unconvincing Finnish Study  

Amazingly, MMR manufacturer Merck has sponsored yet another safety study from Finland.  This latest work by Patja, Peltola and Associates, which was published in the December issue of the Journal of Pediatric Infectious Diseases will surely be used by Governments to rule out an MMR-autism connection.

It should not.

The study, which lasted 14 years, ended in 1996, before parents and physicians had ever heard of an MMR-autism connection. The study never looked at autism and H. Peltola publicly stated that the research was not designed to pick up cases of autism.

Actually, the authors could not have found any cases of autism, even if they tried, because of the study inclusion criteria.

The study, a passive surveillance, only included information reported by health providers to the study’s central office. This method, somewhat similar to the United States’ VAERS reporting, is notorious for its representation of only a tiny proportion of actual cases (perhaps 10%).

In fact, a 1995 study, by members of the UK Public Health Laboratory Service which was published in the Lancet, stressed that passive surveillance is not successful and that active surveillance of adverse events associated with MMR and DPT is imperative

Rebuttal to Wakefield Called 'Weak' with 'Distortions': Shattock

Autism, MMR and 60 Minutes: Another Pediatrician’s Perspective

There is NO long-term safety research proving that MMR does not cause autism.  There is a sole epidemiological study by Taylor et al, often publicized as proving decisively that autism did not increase in the UK after 1988, when MMR was introduced with great fanfare.  This study was financed and ordered by The Medicines Control Agency and The Public Health Laboratory Service.

A noted British statistician whose specialty is medical research, looked carefully at the Taylor study.  He wrote:  “A myth is being created that the Taylor et al study shows that MMR is not triggering autism. The evidence presented in their Lancet paper is [in fact] consistent with the MMR triggering a substantial proportion of autism cases in this North London population.  The study does not find evidence to support an association between MMR and autism onset because of a flaw in the study design.  This does not mean that such an association does not exist.”  

Another Independent Scientist Falls Victim over Findings Against MMR Vaccine

The reason for this expert’s comments is that the “case series design” used in the Taylor study is well known to be statistically unsatisfactory for chronic conditions and inadequate for a small sample (293 confirmed cases).  Even the authors of the study themselves alluded to its methodological problems.

Another paper published in 1999 was deemed to demolish Wakefield’s hypothesis once and for all. Taylor and colleagues [8] identified all 498 known patients with autism spectrum disorders (ASD) in North East London who had been born in 1979 or later. They failed to show any sudden increase in cases of autism with the introduction of MMR vaccine in Britain in 1988.

Wakefield [9] pointed out that although the MMR vaccine was introduced in 1988, there was simultaneously a ‘catch-up’ campaign, targeted at all children, whatever their age, who presumably had not received either monovalent mumps or rubella vaccine. This would have smoothed out the ‘jump’ in incidence associated with the first introduction of the vaccine that was expected. Another factor that would smooth out the ‘jump’ is the variable delay between vaccination and the development of autism mentioned earlier.

One obvious weakness in the analysis of Taylor and coworkers that no one has commented on, is in fitting exponential trends to the data, which is notoriously unreliable. And separating the data into three groups, core autism, atypical autism and Asperger’s syndrome as Taylor and coworkers did, makes it even worse. It is virtually impossible to distinguish between an exponential increase that began in 1979 or in the year of vaccine introduction, 1988.

The time-trend in the increase in autism was confirmed by researchers in the Boston collaborative Drug Surveillance Program, Boston University School of Medicine, based on GP records in the United Kingdom [10]. They found the incidence of newly diagnosed autism increased sevenfold, from 0.3 per 10 000 in 1988 to 2.1 per 10 000 in 1999. (Actually, the peak value of 2.2 was reached in 1997). In 114 boys born in 1988-1993, the risk of autism in 2-5 year old boys increased nearly fourfold, from 8 per 10 000 in 1988 to 29 per 10 000 in 1993.