Minute Investigate: can having a vaccine cause autism?

Mistrust about the effectiveness and safety of vaccines often leads some people to question health professionals, pharmaceutical companies and governments about possible side effects that could harm the health of babies and children.

Recently, an assumption has resurfaced on social media and messaging apps. It is quite possible that you have come across “news” guaranteeing that vaccination can cause autism in children – including when immunization occurs in women who are still pregnant.

In addition to several other speculations, this assumption has been blamed for the reduction in demand for children’s immunization, something that has worried health authorities.

In view of this scenario, the Healthy Minute takes action to verify the pertinent information and clarify, based on the opinions of renowned experts, if the information circulating on the internet is false or true.


What is Autism?

If you are unfamiliar with the term, Autism Spectrum Disorder (ASD), better known only as autism, is a disorder in the child’s neurodevelopment that affects the cortical region of the brain and its diagnosis usually occurs during childhood, close to 3 years old.

The characteristic symptoms are difficulty in communication, little social interaction and the stipulation of restrictive and repetitive behavior patterns.

The causes of autism are not yet fully understood, but experts are investigating the direct relationship with genetics, although environmental interventions have not yet been fully ruled out as potential influencers in the development of ASD.

If you want to know even more about this subject, be sure to check out our full article on autism.

Vaccine and autism: how did this relationship come about?

This relationship between vaccination and autism emerged in 1998, when doctor Andrew Wakefield published an article in The Lancet magazine , stating that 12 children developed autistic behaviors after receiving triple immunization against measles , mumps and rubella .

The association of thimerosal with the involvement of autism was then reinforced. This component is used as a preservative, preventing the growth of bacteria and fungi, and the consequent contamination of medications.

The impasse lies in the fact that thimerosal contains mercury, an element that can cause toxicity to our organism.

However, several subsequent researches have already proven that the low concentration of mercury in vaccines has no harmful potential for our health – which is already a consensus among respected institutions like the World Health Organization, the Institute of Medicine in the USA and the Ministry of Health .

The repercussions of the Wakefield publication hampered vaccination campaigns in several countries. However, as of 2004, studies by different medical institutes have refuted this hypothesis.

Years later, one of the researchers involved in the study publicly stated that he had found no traces of the measles virus in the children analyzed and that Wakefield ignored this information so that the publication would not be harmed.

Before launching the article, Wakefield had also applied for a measles vaccine patent, which would be a competitor to that used for immunization at the time – a fact that represents a conflict of interest between the doctor and the study.

In 2010, the UK’s General Medical Council declared Wakefield unfit to practice as a doctor and revoked his professional record. The magazine published a note apologizing to the scientific community and its readers.

Expert opinion

To find out if there is any possibility that vaccines cause or increase the incidence of autism in children, we sought data from research institutions and experts in the field.

“ Vaccines do not cause autism. Numerous serious studies have been conducted to verify the relationship and none of them found any evidence ”, says Karina Meira Fernandes, master in Biochemistry at the Federal University of Paraná (UFPR) and professor of the Training Course in Vaccination Service in Pharmacies at IBRAS.

“ One of the largest studies was released in 2015 and evaluated 95,727 children in the United States between 2001 and 2012. Analysis of the data showed that vaccination with one or two doses of the triple viral was not associated with an increased risk of ASD at any age. ”, He adds.

According to a 2018 survey by the American Academy of Pediatrics , the American body that regulates the country’s pediatric health, there was also no increase in diagnoses of ASD in children whose mothers received immunization during pregnancy – including against serious infections.

This study analyzed 81,993 medical records regarding the vaccination of pregnant women against tetanus, whooping cough and diphtheria . The results showed rates of 1.5% in the positive diagnosis of ASD in the groups of vaccinated mothers and 1.8% in the groups of mothers who had not been immunized.

“ All the vaccines that are currently offered in the vaccination service have undergone strict standards of demand and quality from the manufacturing laboratories in all their development phases ”, explains Fernandes.

“ Even after developed and commercialized, these vaccines continue to be monitored by pharmacovigilance. This monitoring is carried out mainly by the Ministry of Health, through the Post-Vaccination Adverse Events Surveillance System (EAPV) of the National Immunization Program (PNI) ”, says the master in Biochemistry.

“ As with any medication, vaccines can have adverse events. The most common are: local pain and redness and, sometimes, fever . However, these are not a concern for society in general. Therefore, the benefits of immunization far outweigh the risk of adverse events ”, he concludes.

False or true?

After researching scientific studies and consulting health professionals specialized in immunization, we found that there is no evidence to prove the development of ASD as a consequence of vaccinations – neither when applied to children, nor when immunization occurs in pregnant women.

Therefore, people should not fear vaccination or stop taking their children to be immunized. Medications of this kind are extensively tested before they are released and health authorities monitor their effects to identify possible adversities.

Before sharing alarmist news, it is essential to look for reliable information, from sources that have technical support, or consult the health authorities.

” It is important that parents seek the guidance of pediatricians and other health professionals who are part of the vaccination service to clarify any doubts that may arise “, guides Karina Meira Fernandes.

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