Vaccination and Autism: Is there any connection at all?

Is there any Vaccine-Autism link?

Wondering if it’s safe to vaccinate your kid?

Short answer: No. There is no connection between vaccines and autism.

Then why is there so much fear regarding it? Let us try to educate ourselves with the facts related to the issue and bust the myths.

We’ll start with the basics first.

What is vaccination and how does it work?

Vaccination (or immunization)  is a process in which a germ (killed/weakened) or any part of it (antigen) is introduced to the body, which in turn develops a defense against it. Therefore, we get protection against the disease without having to undergo the risk of death and suffering that comes with the disease.

In 1796, Edward Jenner made a major breakthrough when he pioneered the world’s first vaccine (smallpox vaccine). This later led to the eradication of smallpox, the first and only disease to be eradicated so far. Thereafter, several vaccines have been developed. However, the development of vaccines isn’t quick and easy. They undergo a rigorous development, approval, and safety monitoring process. It’s true that vaccines have been a boon to us. It has led to an unparalleled decrease in the suffering caused by vaccine-preventable diseases.

What is Autism and what causes it?

Autism is a condition that mostly occurs at the onset of childhood. It results in abnormal development of social skills. Autism affects how people interact and communicate with others. There is a broad range of conditions characterized by changes in social skills, repetitive behavior, speech, and nonverbal communication. All of these are included under an umbrella term called autistic spectrum disorder (ASD). According to the Center for Disease Control (CDC), 1 in 59 children was identified with ASD in their ADDM network study. The studies for Asia, Europe, and North America have shown an average prevalence of 1-2%.

What causes autism?

We currently do not know the exact cause of Autism. Scientists are still investigating it. There are many factors that affect the development of the brain and may be responsible for this complex neurodevelopmental condition. These factors could be either genetic or environmental.  According to the CDC and NHS, these are the risk factors for Autism:

A. Genetics

1. Among identical twins, studies have shown that if one child has Autism the other child has a higher risk (36- 95%) of suffering from Autism compared to non-identical twin pairs (0-30%).

2. If parents already have a child with Autism, there is a higher risk of the second child getting affected

3. Autistic Spectrum Disorder(ASD) tend to occur more commonly with certain chromosomal conditions like downs syndrome, fragile X syndrome, and tuberous sclerosis.

 4. Autistic Spectrum Disorder (ASD) tend to co-occur with other developmental, genetic, and neurologic conditions

B. Environmental Triggers

1. Children born to older parents are more likely to be affected by Autism.

2. Babies born prematurely or with low birth weight have a slightly elevated risk.

3. Exposure to alcohol and certain medication in the womb also increases the risk of Autism.

Both CDC and NHS do not mention vaccines as a risk factor for Autism. Also, CDS clearly states that there is no link between vaccines and autism.

No link between Vaccines and Autism – CDC & NHS

Origin of myth linking Autism and Vaccines

In early 1998, Andrew Wakefield, a physician at Royal Free Hospital in London, published an article in The Lancet, claiming to have found the explanation for Autism in the measles virus. He proposed in his paper that the measles virus caused some inflammatory breach in the gut wall that allowed neurotoxic proteins to reach the bloodstream and to the brain. According to his hypothesis, this caused autism. This spread like wildfire, gathering support from lawyers, politicians, and parents groups. It also got widespread media coverage.

However, despite having flaws and weaknesses, this sensational study became common wisdom overnight.

People back then did not realize that the study was riddled with a lot of flaws. This study showed near 100% association between intestinal lesions, autism, and MMR vaccine or Measles infection.  One needed to be cautious in interpreting sensational findings in such a small number of children that too without comparing against a comparison group. Conclusions drawn thereof are not statistically valid.

In 2004, The Lancet refuted the interpretation of the study

In 2005, an investigative reporter alerted The Lancet of the study being grossly flawed by scientific misconduct and conflict of interest. The Lancet investigated the matter and ultimately retracted the article in 2010. British Medical Council also took disciplinary action against Dr. Wakefield.

Several pieces of researches have scientifically rejected the hypothesis of a relation between vaccine and virus. However, this could not reassure people. They thought that, if not the virus, another vaccine component must be responsible. A hypothesis suggesting the mercury-containing preservative ‘Thiomersal’ in MMR (Measles, Mumps, and Rubella) vaccines was the cause of it. This theory gathered momentum, that too without any scientific backing.

So, we see that it was flawed and misleading research that sparked the controversy.

The fall out:

However, in the meantime, anti-vaccine movement groups started spreading even more rumors, by using fallacious and anecdotal reports. In an attempt to protect their children, parents became more likely to omit vaccine, rather than to take the risk of giving it. For many of them, it was the case of broken trust. They just believed that something is wrong with the vaccines. It led to a decrease in the acceptance of the vaccine. This later resulted in a resurgence of vaccine-preventable diseases.

If you are interested in reading it in more detail, I recommend you to read this beautifully written scientific journal article “Vaccination as a cause of autism—myths and controversies”

Are we sure there is no Vaccine-Autism link?

We have seen that flawed research sparked this controversy. But, as of today, is there any evidence to say that there is no link between Vaccines and Autism?

Consider these points,

1. After the Dr. Wakefield publication, people stopped vaccinating their children. Vaccination rates sharply fell – but the prevalence of Autism kept on increasing (you expect autism to decrease in case there is a link)

2. After withdrawing Thimerosal from vaccines, autism did not decrease – it rather kept on increasing

3. A 2003 study of more than 140,000 children showed no relationship between Thimerosal and autism

4. In 2004, the IOM panel had reviewed over 200 epidemiological and biological studies for any link between vaccines and autism and found no link.

5. In 2014: A Scientific metanalysis published on Vaccine involving 1,256,407 children concluded that neither Thiomersal or MMR vaccine had any link to autism.

So, Yes. There is convincing evidence that vaccines have nothing to do with causing Autism.

Summary:

Scientific studies have convincingly shown that there is no link between vaccines and autism. Period. There is no reason for parents to worry. However, this mammoth of evidence also has failed to halt the Vaccine-Autism theories. Almost one in 4 Americans still believe that this link exists.

But we cannot let the lost diseases come back, while we are fighting the Vaccine-Autism war. Prominent people and religious leaders will have to come forward to bridge the gap between Science and the Citizens. We cannot afford to say no to vaccines… at least, not without any evidence.