Childhood vaccination has been a subject of controversy among parents since 1998. The topic is as contentious if not more so than working versus staying at home and bottle versus breast-feeding. Vaccinations are heralded by the medical, scientific and public health communities as being among the top ten public health achievements of the 20th century. Millions of lives have been saved by preventing infections with deadly diseases. Countless cases of disabilities have also been prevented by halting the spread of infectious diseases through the use of routine vaccinations during childhood. One dishonest study by a British researcher threatened to halt this public health achievement and put the well-being and lives of countless people at risk. The most recent Centers for Disease Control estimates show that 1 of every 68 children have an autism diagnosis. As the rate of autism has increased, ensuring that parents have access to correct, honest and ethical information about vaccinations is essential to the public health.
The Article That Caused Vaccine Fears
In 1998, British surgeon Andrew Wakefield published an article in the renowned journal The Lancet. In the article, Wakefield presented evidence later found to be dishonest and erroneous that revealed eight of 12 children may have developed autism and bowel disease after receiving the measles, mumps and rubella (MMR) vaccinations. Because parents of autistic children and scientists had searched in vain for a cause behind autism, the small Wakefield study went viral. Seemingly overnight, celebrities and parents alike turned to the MMR vaccine as the cause of their children’s ailments.
Repercussions of the Wakefield Article
As the Wakefield study went mainstream, he became a household name. Parents began to refuse the MMR vaccination with some opting for an alternative vaccination timetable while other parents refused any and all vaccines for their children. As a result, vaccination rates in the United States and Canada significantly declined. When fewer members of a population are vaccinated, outbreaks of disease increase. In recent months and years, outbreaks and epidemics of vaccine-preventable diseases including whooping cough (pertussis), measles and mumps have occurred throughout North America. Children and teenagers have developed serious complications such as deafness and seizures, and many have died due to contracting a disease that could have been prevented by following the CDC’s recommended vaccination schedule. It is for these reasons that physicians and researchers such as University of Sydney’s Associate Professor Guy Eslick delved further into the issue.
Disproving and Debunking the Wakefield Article
As soon as the Wakefield study was published, medical researchers attempted to replicate the findings. None were able to do so. As article after article from researchers around the world poured into scientific journals, none were supportive of Wakefield’s findings. Eventually, Wakefield was accused of dishonesty and unethical behavior and The Lancet retracted the paper and published an apology. That, however, did little to dissuade people who developed firm beliefs about the issue. University of Sydney scientist Associate Professor Guy Eslick set out to combine the hundreds of individual studies in what statisticians and epidemiologists refer to as a meta-analysis.
Mechanics of the University of Sydney Analysis
Associate Professor Guy Eslick at the Sydney Medical School put together all available published data from seven studies involving more than 1.25 million children around the world. He concluded that there was no evidence to support a relationship between common vaccines for measles, mumps, rubella, diphtheria, tetanus and whooping cough and the development of autism and related disorders such as Asperger’s. In order to conduct the review, which is in press in the journal Vaccine, Eslick used data from publicly available research studies. He and his co-authors identified relevant articles using search terms associated with autism diagnoses. Data was collected from the published articles and examined for publication bias. Pooled odds ratios were calculated for the effect of vaccinations on the development of autism using a random effects model. The data was also divided into sub-groups to examine the risk of an autism diagnosis alone. The subgroups were after the MMR vaccine, after mercury exposure or after exposure to a vaccine containing thimerosal preservative. The group conducted vigorous statistical analyses of the data including tests of heterogeneity, Egger’s regression model for publication bias and Rosenthal’s fail-safe number for publication bias. Eslick and the group thoroughly examined the risk of publication bias because of the well-known fact that studies finding null results are less likely to be published than those finding non-null results.
Results of the University of Sydney Analysis
After eliminating data from studies that were not related to autism or that showed any bias of publication, Eslick and his team were left with five cohort studies and five case control studies. They pooled the data from these studies and found no evidence of a link between autism and vaccinations. Of special importance is the fact that four of the five cohort studies were of large populations and had sound scientific methodology. Since no evidence of any linkage between autism and vaccinations were found in the meta-analysis, the currently recommended immunization schedule should be adhered to by children as well as adults.
Are There Any Risks to Vaccinations?
While there is no evidence linking vaccinations to autism, vaccinations do occasionally cause side-effects such as fever or rash, which are generally mild and brief in nature. Only rarely is there a serious medical complication resulting from a routine childhood vaccination. Any adverse events after vaccination are reportable to the Vaccine Adverse Event Reporting System which is accessible by the public as well as physicians and researchers.
The Benefits of Routine Immunizations and Travel Vaccinations
Vaccines offer the ability to protect oneself against disease without having to acquire immunity through a natural infection. When a person becomes naturally infected with a disease, there is a real risk of complications and death. Thanks to routine childhood vaccinations, cases of serious infections such as measles, mumps, rubella, diphtheria, whooping cough, tetanus, polio and Haemophilus influenzae type b, have declined by 91 to 100 percent. Preventing disease is less economically costly than treating it. For every dollar invested in vaccinations, $5 to $11 is saved in healthcare costs. Once a high number of people in a population are vaccinated against a disease, that disease is much less likely to cause an outbreak. This type of immunity, referred to as herd immunity, helps to protect those who are unable to be vaccinated for medical reasons.
Staying Up to Date on Your Vaccinations
If you’re behind on any vaccinations or you’re planning an international trip, a pre-travel health exam at a Passport Health clinic can get you up to date. Travel health specialists offer travel vaccines, medications and guidance on packing travel supplies for optimal health.
University of Sydney: Vaccines Are Not Associated with Autism: An Evidence Based Meta Analysis of Case Control and Cohort Studies (in press)
Centers for Disease Control: Vaccine Safety and Concerns About Autism
New York Post: No Links Between Autism and Vaccinations: Study
CDC Study Debunks Vaccine Autism Link
Herald Sun: Childhood Vaccinations Not Linked to Development of Autism, University of Sydney Finds
National Institute of Allergy and Infectious Diseases: Vaccine Benefits