Measles: The Science behind the Myth of Anti Vax Movement
Vaccines are not devoid of side effects, but the measles vaccine autism link is often raise by the same group of parents who never saw a clinical case of measles, mumps or rubella.
In a previous article, we had discussed exactly what the Measles virus is, how it affects infected individuals, and some potent side effects. To summarize, the Measles virus (scientifically known as Morbillivirus measles) is highly contagious (90% of those individuals unprotected either through vaccination failure or through exposure to infection - i.e., the had measles) will contract the disease. While in most it remains a high fever with a rash, the potential complications are quite severe and include encephalitis (brain infection) that is fatal in 1/1000, conjunctivitis (that may lead to blindness), and a mortality rate of 1/1000. Adults will have more severe manifestations of the disease when they do in fact contract measles.
So why would anyone ever avoid the vaccination that prevents these complications?
The common argument – heard again and again on various social media platforms (Facebook being the major offender) is that the measles virus causes “autism” and must, therefore, be avoided.
But is this really true?
What is Autism? – Autism spectrum disorder (and yes – it’s a spectrum because of the wide variety of clinical signs manifested in affected children) is a developmental disorder that may have a range of symptoms that vary widely. Common symptoms (but these may not be seen in all autistic patients) include difficulty with communication, difficulty with social interactions, obsessive interests, and repetitive behaviors. We will discuss the three major forms of autism (Asperger Syndroms, Persistent Developmental Disorder not otherwise specified, and Autistic Disorder) – in a different article in more detail.
There are currently over 200,000 cases of Autism Spectrum disorder in the United States today, and the number of cases continue to increase every year. Established risk factors include advanced maternal age, advanced paternal age, smoking during pregnancy, preterm labor (baby born before 37 weeks), low birth weight, and decreased head circumference when the child was born. These risk factors have been statistically shown to be strongly associated with autism (and a variety of other conditions).
As we know – the average age of parents and starting a family in the United States has been on the rise for the last 20 years. Americans are choosing to start families later, causing a natural increase in the average age of both parents. In 2018 the average age of the first time mother was 26, up from 21 in 1972; the average age of the first time father was 27, up from 24 in 19722. Children born to older parents will already be at risk for a variety of congenital conditions (we will discuss this in a separate article), including Autism spectral disorder.
But does the Mobillivirus measles cause Autism?
In the late 1990s – 4 studies did indeed show a statistical association between Autism and the MMR (Measles Mumps Rubella) vaccine. These were largely published and distributed; this remains the basis for a large number of parents refusing to vaccinate their children at that time (1996-2001).
Unfortunately, the limitations and drawbacks of these four studies are not emphasized adequately. The sample size of these studies was limited, and statistical power (the statistical strength of the MMR being a causative established risk factor for Autism) is very low.
Which is why the American Association of Autism refuses to state any association between Autism and the MMR virus.
A large number of more recent studies have effectively countered the 4 older studies supporting association between MMR and autism. The largest most recently published study from Denmark followed over 657,461 children between 1999-2010 found no link between autism the MMR virus. Additional 4 case control studies and 2 cohort studies from Denmark, Poland, Japan, the UK, and the United States have failed to show any association between the MMR vaccine and Autism.
By choosing not to allow our children to be vaccinated, we risk exposing them to measles virus – that has possibly severe consequences. The extremely contagious nature of Morbillus measles means 9/10 of those unvaccinated exposed to the virus will contract the disease – causing severe quarantine measures in those states where measles outbreaks have been documented.
Vaccines are not completely devoid of side effects or untoward reactions. Psychologically, the stress of watching one’s infant being injected with any needle is never easy. The majority are due to adverse reactions from the various adjuvants added to the actual vaccine – such as preservatives (to prevent contamination), adjuvants (to stimulate the body’s response to the actual vaccine), and stabilizers (to keep the vaccine potent). Reactions to these additives cause an allergic type stimulus in the body that in rare cases has a more severe manifestation.
Pediatricians are seeing a larger number of parents refusing vaccines to their children, often by considering them to be "unsafe." Unfortunately, this will often be the same group of parents who never saw a clinical case of measles, mumps, or rubella in their life. The widespread clinical consequences of measles, mumps and rubella will have a spectrum of effects – affecting the brain, the heart, the eyes, and weakened immunity from exposure to these viruses that have no cure – only supportive management.
So this is the true science behind the myth of the antivaxxing movement, widely publicized on social media and considered by most as the basis of the current widespread measles outbreak in America.
1. Autism Speaks – Offical webpage of the Autism Speaks Organization
2. The New York Times, August 4 2018 page 4.
3. “Measles, Mumps, and Rubella Vaccination and Autism: a Nationwide Cohort Study.” Hviid et al. Annals of Internal Medicine, March 5 2019.
4. “Autism and Measles, Mumps, Rubella Vaccine: No Epidemiological Correlation”. Taylor et al. The Lancet. June 12, 1999.
5. Cdc.gov. Vaccines: official online publication. 2019