No Link Between H1N1 Flu Vaccine and Autism: Study

Receiving the H1N1 “swine flu” vaccine during pregnancy does not appear to increase the risk that the baby will be autistic, according to the findings of a large Swedish study.

Concerns have existed about the potential side effects of the H1N1 vaccine during pregnancy, but researchers indicate that there is no evidence of a link between the vaccine and autism in findings published this week in the Annals of Internal Medicine.

Researchers set out to examine the risk for autism spectrum disorders (ASD) among children born to mothers who were vaccinated against H1N1 during pregnancy.

The study included patients from seven health care regions in Sweden and included live births between October 2009 and September 2010. A total of 40,000 infants who were prenatally exposed to H1N1 vaccine were a part of the study.

The data indicated 1% of infants who were exposed to the swine flu vaccine received a later diagnosis for autism. Comparatively, 1.1% of infants who were not exposed to the vaccine during pregnancy received a diagnosis for autism.

The study concluded prenatal exposure to the H1N1 vaccine was not linked to later autism spectrum diagnosis. Researchers reassured pregnant women worried about the side effects of the flu vaccine that there is no evidence it leads to autism.

Concerns over vaccines causing autism have powered the so-called “anti-vaxxer” movement in recent years, which believes that the risk of vaccines is a bigger threat than eliminating crippling and sometimes deadly childhood illnesses like measles and polio.

However, much of the concern regarding the association between autism and vaccines came from a now-discredited study published in 1998 by Dr. Andrew Wakefield, who has been accused of having falsified data to make it appear that there was a connection.

Wakefield was stripped of his medical license in 2010, and his study was retracted and deemed a fraud. However, concerns over a connection between autism and vaccines persist.

In the case of the H1N1 vaccine, pregnant women’s confidence is especially important because they face seven times the risk of being hospitalized with pneumonia if they catch the flu. Getting the flu during pregnancy can also lead to increased risk of premature delivery, which can lead to myriad side effects and health concerns for the infant. Getting the flu vaccine is one of the key ways a pregnant woman can protect herself from serious complications.

Autism spectrum disorders (ASD) are developmental disorders characterized by problems with social interactions and communication. Children with autism often complete repetitive and restrictive behaviors. New research indicates the number of children being diagnosed with autism is increasing. Now, one in every 59 children are on the spectrum.

“This large cohort study found no association between maternal H1N1 vaccination during pregnancy and risk for ASD in the offspring,” wrote study authors.