As the rate of ASD rises worldwide, parents and professionals are trying
to find causes that induce autism in children. With the influence of anti-vaccine
activists and celebrity alike, claiming that children developed autism
following an immunization shot,
with no scientific evidences, parents are giving in to emotions and fears. Their concerns on environmental
factors such as vaccines causing autism are legitimate although totally
unfounded and false.
Where does this myth come from?
The vaccine theory suspected to be responsible for autism development is
centered on three main factors:
- the measles-mumps-rubella (MMR) vaccine
- the thimerosal, an ethylmercury-containing preservative in some vaccines
- a large number of vaccines currently administrated to infants and toddlers
In 1998, a British study published in
The Lancet by Dr Wakefield, described autism symptoms in eight children within a
month after receiving a MMR shot. The author postulates that MMR causes
intestinal inflammation by damaging the intestinal lining, which allows
the entrance of proteins into the bloodstream and will ultimately attack
the brain. This study lacking several controls and supporting data was
then totally discredited.
Thimerosal is suspected to be toxic to the central nervous system. But
MMR, like all live vaccines, does not contain this component. Furthermore,
despite the absence of data suggesting harm from quantities of ethylmercury
contained in vaccines,
the American Academy of Pediatrics and the Public Health Service recommended the immediate removal of mercury from all vaccines given to
young infants in 1999.
A new theory emerged and proposed that too many vaccines overwhelm or weaken
the immune system. Vaccine represent a fraction of what a child’s
immune system is exposed on a daily basis. Indeed, we have all complained
about our kids getting sick every other week (runny nose, sore throat,
fever), especially when they are in day care, exposed to virus and infected
up to six times a year.
Vaccines do not weaken a child’s immune system but infection with
vaccine-preventable disease could induce a sensitivity and predispose
a child to infections with other pathogens.
No connections between MMR vaccine and Autism confirmed in high risk population
For the past 16 years, over 20 epidemiologic studies have shown that
MMR vaccine is not associated with autism development (1-3). In particular, Uno and collaborators found that neither MMR vaccine
administration nor the number of vaccines injections were associated with
an increased rate of new-onset autism (4).
The latest study published last week in the Journal of
the American Medical Association go a step further by investigating the potential connection between MMR
vaccines and Autism in children
who are at higher risk for developing autism because of an older sibling affected by the disorder (5). By sharing genetics
with their older autistic sibling, this population group is more prone
to develop autistic behaviors.
The study including almost 100 000 children (insurance claim from a large
commercial health plan) with at least one older sibling (healthy or autistic
in 2.01% of cases) found that toddlers vaccinated against MMR
don’t have an increased risk of developing autism whether or not there are autistic children among the siblings.
Many parents of autistic children claimed that MMR shot made their symptoms
much worse despite a lack of scientific evidences. Although the latter
study does not investigate that point, we cannot rule out the possibility
that immunization, in specific cases with underlying genetic predispositions
or autoimmune diseases, could trigger the onset of autism symptoms.
Unfortunately, concerns about MMR safety in family with an autistic child
has led to a significant decrease of vaccination among younger siblings
as reported lately.
This work confirms that causes leading to Autism do not occur during the
first few years of a child but take place earlier. This strengthens our theory
at Braverman Reproductive Immunology:
“Genetic predispositions to autism are unraveled in utero by a maternal
systemic inflammation during pregnancy resulting from an infection or
autoimmune diseases and ultimately lead to an impairment in fetal neurodevelopment.”
- Farrington CP, Miller E, Taylor B. MMR and autism: further evidence against
a causal association. Vaccine. 2001; 19(27):3632–3635
- Mrozek-Budzyn D, Kie1tyka A, Majewska R. Lack of association between measlesmumps-
rubella vaccination and autism in children: a case-control study. Pediatr
Infect Dis J. 2010; 29(5):397–400.
- Smeeth L, Cook C, Fombonne E, et al. MMR vaccination and pervasive developmental
disorders: a case-control study. Lancet. 2004; 364(9438): 963–969.
- Uno Y, Uchiyama T, Kurosawa M, Aleksic B, Ozaki N. The combined measles,
mumps, and rubella vaccines and the total number of vaccines are not associated
with developmentof autism spectrum disorder: the first case–control
study in Asia. Vaccine. 2012; 30(28):4292– 4298.
- Jain A, Marshall J, Buikema A, Bancroft T, Kelly JP, Newschaffer CJ. Autism
occurrence by MMR Vaccine Status Among US Children With Older Siblings
With and without Autism. JAMA. 2015 Apr 21; 313(15):1534-1540.
- Diamond B, Honig G, Mader S, Brimberg L, Volpe BT. Brain-reactive antibodies
and disease. Annu Rev Immunol. 2013; 31:345-85.
- Singer HS, Morris C, Gause C, Pollard M, Zimmerman AW, Pletnikov M. Prenatal
exposure to antibodies from mothers of children with autism produces neurobehavioral
alterations: A pregnant dam mouse model. J Neuroimmunol 2009; 211: 39–48.
- Martin LA, Ashwood P, Braunschweig D, Cabanlit M, Van de Water J, Amaral
DG. Stereotypies and hyperactivity in rhesus monkeys exposed to IgG from
mothers of children with autism. Brain Behavior Immunity 2008; 22: 806–816.
- Pardo CA, Eberhart CG. The neurobiology of autism. Brain Pathol 2007; 17: