A 24-year study of more than 1.2 million Danish children adds to the already considerable evidence finding no tie between exposure to aluminum-adjuvanted childhood vaccines and autoimmune, atopic or allergic, or neurodevelopmental conditions such as autism.
The study, published today in the Annals of Internal Medicine, comes less than a month after US Health and Human Services (HHS) Secretary Robert F. Kennedy Jr. reportedly asked a government vaccines advisory group to scrutinize dozens of aluminum-containing vaccines that have been in use for nearly 100 years.
Aluminum-based adjuvants are often used in inactivated vaccines, including childhood vaccines against diphtheria, tetanus, and pertussis (Tdap), Haemophilus influenzae type b (Hib), pneumococcal conjugate vaccine (PCV), and hepatitis A and B to boost immune responses, the study authors noted.
“Although immunization with aluminum-adsorbed vaccines in children has been used worldwide for many decades and is generally considered safe, concerns about potential harms continue to resurface,” they wrote.
Only 1.2% had received no aluminum-containing vaccines
Researchers at the Statens Serum Institut in Copenhagen led the nationwide study, which used registry data on childhood vaccinations and aluminum content, outcomes, and potential confounding factors in the first 2 years of life among more than 1.2 million children born in Denmark from 1997 to 2018. Median age at the end of the 2-year follow-up period was 5 years.
Only 15,237 children (1.2%) received no aluminum-adjuvanted vaccines before age 2. Each aluminum-adjuvanted vaccine dose contained 0.125 to 1.00 milligram (mg) of aluminum. The total vaccine-related aluminum exposure by age 2 varied by birth year (median, 3 mg).
During follow-up, the team looked for vaccine-related events involving 50 chronic conditions, including 36 autoimmune (dermatologic, endocrinologic, hematologic, gastrointestinal, and rheumatic), 9 atopic or allergic (asthma, atopic dermatitis, rhino conjunctivitis, and allergy), and 5 neurodevelopmental (autism spectrum disorder and attention deficit hyperactivity disorder).
Very low risk of any condition
The researchers found no association between cumulative aluminum exposure in vaccines in the first 2 years of life and increased risk of any of the 50 chronic conditions.
This nationwide cohort study did not find evidence supporting an increased risk for autoimmune, atopic or allergic, or neurodevelopmental disorders associated with early childhood exposure to aluminum-adsorbed vaccines.
For groups of combined outcomes, adjusted hazard ratios per 1-milligram increase in aluminum exposure were 0.98 (95% confidence interval [CI], 0.94 to 1.02) for any autoimmune disorder, 0.99 (95% CI, 0.98 to 1.01) for any atopic or allergic disorder, and 0.93 (95% CI, 0.90 to 0.97) for any neurodevelopmental disorder. For most individually analyzed disorders, the upper limits of the 95% CIs were incompatible with relative increases higher than 10% for 19 disorders, 30% for 7 disorders, and 31% to 79% for the 4 remaining conditions.
“This nationwide cohort study did not find evidence supporting an increased risk for autoimmune, atopic or allergic, or neurodevelopmental disorders associated with early childhood exposure to aluminum-adsorbed vaccines,” the authors wrote. “For most outcomes, the findings were inconsistent with moderate to large relative increases in risk, although small relative effects, particularly for some rarer disorders, could not be statistically excluded.”
Source link
