Routine childhood vaccinations are not associated with an increased risk of epilepsy in young children, according to a new study led by the US Centers for Disease Control and Prevention (CDC).
The study, published in The Journal of Pediatrics, also found that aluminum used as vaccine adjuvants does not raise the risk of the neurological condition.
“Incident epilepsy was not associated with up-to-date vaccination status or cumulative vaccine aluminum exposure among children under four years of age,” the researchers said. The team included scientists from the Marshfield Clinic Research Institute in the United States.
The study analysed 2,089 children diagnosed with epilepsy between the ages of one and four years and compared them with 20,139 children without epilepsy, matched by age, sex and healthcare site.
Most of the children were boys (54 per cent), and a majority were aged between one year and 23 months (69 per cent). Researchers found no increased risk of epilepsy associated with adherence to the childhood vaccination schedule.
To assess vaccine exposure, the team examined routine immunisation schedules and cumulative aluminum exposure from vaccine adjuvants, measured in milligrams.
Aluminum salts — including aluminum hydroxide, amorphous aluminum hydroxyphosphate sulfate, aluminum phosphate, combined aluminum hydroxide and aluminum phosphate, and aluminum potassium sulfate — are commonly used as vaccine adjuvants to enhance immune response, though they have been the subject of safety concerns.
However, the study found that neither vaccination status nor aluminum exposure was associated with a higher risk of epilepsy.
“The adjusted odds ratios for both measures did not exceed 1.0. Children with established risk factors for epilepsy — including premature birth, family history of epilepsy and underlying neurological or medical conditions — had substantially higher odds of developing the condition,” the researchers said.
A subgroup analysis suggested that very young infants (1–2 months old) who received vaccines containing the combined aluminum hydroxide and aluminum phosphate adjuvant appeared to have roughly twice the odds of an epilepsy diagnosis compared with those who did not, but the result did not reach statistical significance.
“Overall, this study provides additional reassurance about the safety of the childhood vaccine schedule at a time when vaccination coverage has declined in some populations,” the researchers said.
“These findings may help healthcare providers communicate with parents concerned about potential epilepsy risks,” they added.
— IANS
