Fact Check: Vaccines cause autism

Fact Check: "Vaccines cause autism"

What We Know

The claim that vaccines cause autism has been extensively studied and debunked by numerous scientific investigations. According to the CDC, there is no evidence linking vaccines to autism spectrum disorder (ASD). A comprehensive review by the National Academy of Medicine found that vaccines are safe, with rare exceptions, and that no vaccine ingredients have been associated with ASD. Additionally, a 2013 CDC study examined the total amount of antigens received from vaccines in children with and without ASD, concluding that there was no difference between the two groups.

One specific ingredient often scrutinized is thimerosal, a mercury-based preservative. A 2004 review by the Institute of Medicine concluded that the evidence did not support a causal relationship between thimerosal-containing vaccines and autism. Furthermore, multiple studies funded by the CDC have consistently found no link between thimerosal and ASD, as well as between the measles, mumps, and rubella (MMR) vaccine and autism (Gabis et al.).

Analysis

The overwhelming consensus among health professionals and researchers is that there is no causal link between vaccines and autism. The claim largely stems from a now-retracted study published in 1998 that falsely suggested a connection between the MMR vaccine and autism. This study has been criticized for its methodological flaws and ethical violations, leading to its discreditation (Johns Hopkins).

Recent literature, including a meta-analysis published in 2025, reinforces that the supposed association is unfounded. The persistence of this myth has been attributed to factors such as the timing of autism diagnoses, which often coincide with the vaccination schedule, leading to misconceptions among parents (National Autism Center).

Sources that support the claim often lack rigorous scientific backing and are frequently criticized for their reliability. For example, the American Academy of Pediatrics has stated that claims linking vaccines to autism are based on flawed studies. The scientific community continues to emphasize the importance of vaccination for public health, particularly in light of recent measles outbreaks attributed to declining vaccination rates (NBC News).

Conclusion

The claim that vaccines cause autism is False. Extensive research has consistently shown no causal relationship between vaccines and autism spectrum disorder. The persistence of this myth poses a significant public health risk, as it contributes to vaccine hesitancy and outbreaks of preventable diseases. The scientific consensus is clear: vaccines are safe and effective, and they do not cause autism.