Neurodevelopmental disorders after thimerosal-containing vaccines: a brief communication

Area of Science:

• Epidemiology
• Toxicology
• Pediatrics

Background:

• Thimerosal, a mercury-containing preservative, has been used in vaccines.
• Concerns exist regarding potential links between thimerosal exposure and neurodevelopmental disorders in children.
• Previous research on this association has yielded conflicting results.

Purpose of the Study:

• To investigate the association between thimerosal exposure from vaccines and the incidence of neurodevelopmental disorders.
• To analyze large-scale epidemiological data to assess potential risks.

Main Methods:

• Utilized the Vaccine Adverse Events Reporting System (VAERS) database, encompassing millions of vaccine doses administered in the U.S.
• Compared incidence rates of neurodevelopmental disorders following thimerosal-containing diphtheria, tetanus, and acellular pertussis (DTaP) vaccines versus thimerosal-free DTaP vaccines.
• Employed statistical analyses, including relative risk calculations and bias controls.

Main Results:

• Found statistically significant increases in the incidence of autism (RR=6.0), mental retardation (RR=6.1), and speech disorders (RR=2.2) associated with thimerosal-containing DTaP vaccines.
• Observed higher reporting of autism and speech disorders in males compared to females with thimerosal-containing DTaP vaccines.
• No significant differences in acute adverse reactions (e.g., deaths, seizures, gastroenteritis) were found between thimerosal-containing and thimerosal-free DTaP vaccines.

Conclusions:

• The study provides epidemiologic evidence suggesting an association between thimerosal in DTaP vaccines and an increased risk of neurodevelopmental disorders.
• Further research is recommended to confirm and expand upon these findings.
• The findings highlight the need for continued investigation into vaccine components and their potential long-term health effects.