Autism and Shots
In 1998, Andrew Wakefield and a handful of his colleagues realsed a series of papers in the Lancet, which gave the idea that MMR shots could lead to backpedaling in a child’s development and missing important milestones in children. Despite the size of the example, the wild layout, and the opinionated basis of the paper, it got wide publicity, and MMR vaccinations began to disappear because parents were worried about the danger of autism after the shot.
Almost right afterward, medical cases were performed and released, arguing against the possible links between shots and autism. The idea that the MMR vaccine may trigger autism was also questioned because a major key point with the two is almost predestined: both events, early childhood shots and autism, occur in early childhood.
The surprising thing to most believers in the study was a short drawback of the interpretation of the original data by 10 of the 12 co-authors of the paper. The following was stated in the withdrawal, “no definite cause was drawn between shots and autism as the data was incomplete and unreliable”. This was paired with an apology by the Lancet that Wakefield had been bribed by lawyers of parents suing for the shot causing their children’s autism. However, the Lancet blamed Wakefield and his colleagues for the decline in the MMR vaccine rates.
The Lancet completely withdrew the Wakefield case in 2010, coming clean that most of the evidence in Wakefield’s studies were incorrect. Wakefield was held guilty of performing cases of selecting evidence to present in the paper, and discriminating against autistic people. This drawback was posted as a small, anonymous paragraph in the journal, on behalf of the editors.
The final installment of this chain of unfortunate events is the realization that Wakefield and his accomplices were guilty of presenting false evidence. The British Medical Journal has released a journal about the exposure of the fraud, which seems to be for publicity. It is a matter of worry that the exposé was a result of journalistic investigation, rather than academic vigilance followed by the institution of corrective measures. Readers may be intrigued to know that the journalist that was a part of the Wakefield case, Brian Deer, had earlier reported on the false report of mercury (in vaccines) in the cause of autism. However, Deer had not played an investigative role in that report.
There has been enormous argument having to do with the possibility of a link between childhood vaccinations and autism. This has in past years become a major public health issue with vaccine preventable diseases increasing in the community due to the fear of a ‘link’ between vaccinations and autism. Eligible studies assessed the relationship between vaccine administration and the subsequent development of autism or autism spectrum disorders (ASD). Two reviewers extracted data on study characteristics, methods, and outcomes. Disagreement was resolved by consensus with another author. Five cohort studies involving 1,256,407 children, and five case-control studies involving 9,920 children were included in this analysis. The cohort data revealed no relationship between vaccination and autism, nor was there a relationship between autism and MMR shot, or mercury. Similarly the case-control data found no evidence for increased risk of developing autism or ASD following MMR, Hg, or mercury exposure when grouped by condition or grouped by exposure type. Findings of this meta-analysis suggest that vaccinations are not associated with the development of autism or autism spectrum disorder. Furthermore, the components of the vaccines (mercury) or multiple vaccines (MMR) are not associated with the development of autism or autism spectrum disorder.
Two doses of measles-mumps-rubella (MMR) vaccine are currently advised for children in the United States: the first at age 12 to 15 months and the second at age 4 to 6 years. Although a substantial body of research over the last 15 years has found no link between the MMR vaccine and autism spectrum disorders (ASD), parents and others continue to associate the vaccine with ASD.5 Parents cite vaccinations, especially MMR, as a cause of ASD6 and have deferred or refused vaccinations for their children as a result. Lower vaccination levels threaten public health by reducing both individual and herd immunity and have been associated with several recent outbreaks of measles, with most cases occurring among unvaccinated individuals.
Families with a child affected by ASD may be particularly concerned about reports linking MMR and ASD, despite the lack of evidence. Surveys of parents who have children with ASD suggest that many believe the MMR vaccine was a contributing cause. This belief, combined with knowing that younger siblings of children with ASD are already at higher genetic risk for ASD compared with the general population,12- 14 might prompt these parents to avoid vaccinating their younger children. In a recent survey of 486 parents of children with ASD, nearly 20% had declined or delayed MMR immunization in the younger siblings of these children.15 Furthermore, a Canadian study of 98 younger siblings of children with ASD found that younger siblings were less likely to be fully MMR immunized when compared with their older siblings with ASD. However, there were no statistically significant differences in rates of ASD diagnosis between immunized and nonimmunized children.10 To our knowledge, this very small study is alone in examining MMR immunization and ASD outcomes among the younger siblings of children with ASD.
Index children were identified among commercially insured enrollees who had both medical and pharmacy coverage and included all children in the database born between January 1, 2001, and December 31, 2007, who were continuously enrolled in the health plan from birth to at least 5 years of age and who also had an older sibling continuously enrolled in the health plan for at least 6 months between the beginning and end of the study period (January 1, 1997-December 31, 2012). Older siblings of index children were identified using a family identifier variable associated with the insurance policy; siblings had to be between 6 months and 17 years older than the index child to be included.
Because the recommended age of first MMR dose administration is 12 to 15 months, and 4 to 6 years for the second dose, relative risks (RRs) were estimated to compare ASD status in children receiving 1 dose of MMR at ages 2, 3, 4, and 5 years and 2 doses at age 5 years vs those who were unvaccinated at those ages (2-dose RRs at age 4 years would only include those children who received the second dose by their fourth birthday). Separate RRs were estimated for children with older siblings with and without ASD. Since no children were lost to follow-up before reaching age 5, unadjusted RRs were reported as cumulative incidence rate ratios by taking the ratio of the proportion of children who had an ASD diagnosis in an exposed group (either 1 MMR dose or 2 MMR doses) to the proportion of children who had an ASD diagnosis in the unvaccinated group at a given age.
Adjusted RRs were reported as hazard rate ratios estimated from a single Cox proportional hazard regression model that used age since birth as the time scale and included MMR receipt as a time-varying covariate ascribing follow-up time to either the unvaccinated group, the 1-dose group, or the 2-dose group, depending on immunization status at any given age. An interaction term between MMR receipt and older sibling ASD status was included to allow adjusted RRs to vary by older sibling ASD status. In addition, interactions between MMR receipt and age (to relax the proportionality assumption and allow hazard ratios [HRs] to vary by age), as well as a 3-way interaction between MMR receipt, age, and older sibling ASD status, were tested for possible inclusion in the final model.
The logic that the MMR vaccine may trigger autism was also questioned because a temporal link between the two is almost predestined: both events, MMR vaccines and autism, occur in early childhood.
Two doses of measles-mumps-rubella vaccine are currently recommended for children in the United States: the first at age 12 to 15 months and the second at age 4 to 6 years.1 Although a substantial body of research over the last 15 years has found no link between the MMR vaccine and autism spectrum disorders ,2- 4 parents and others continue to associate the vaccine with ASD.5 Parents cite vaccinations, especially MMR, as a cause of ASD6 and have deferred or refused vaccinations for their children as a result.7,8 Lower vaccination levels threaten public health by reducing both individual and herd immunity and have been associated with several recent outbreaks of measles, with most cases occurring among unvaccinated individuals.9 Families with a child affected by ASD may be particularly concerned about reports linking MMR and ASD, despite the lack of evidence.10 Surveys of parents who have children with ASD suggest that many believe the MMR vaccine was a contributing cause.11 This belief, combined with knowing that younger siblings of children with ASD are already at higher genetic risk for ASD compared with the general population,12- 14 might prompt these parents to avoid vaccinating their younger children.
In a recent survey of 486 parents of children with ASD, nearly 20% had declined or delayed MMR immunization in the younger siblings of these children.15 Furthermore, a Canadian study of 98 younger siblings of children with ASD found that younger siblings were less likely to be fully MMR immunized when compared with their older siblings with ASD. Since no children were lost to follow-up before reaching age 5, unadjusted RRs were reported as cumulative incidence rate ratios by taking the ratio of the proportion of children who had an ASD diagnosis in an exposed group to the proportion of children who had an ASD diagnosis in the unvaccinated group at a given age.
...(download the rest of the essay above)