On Apr. 30, 2024, a meta-analysis of six randomized controlled trials in JAMA Neurology found no increase in seizures in the month following COVID vaccination. The study compared the incidence of new-onset seizures between the 63,521 vaccine and 54,919 placebo recipients involved in randomized controlled trials conducted in the last 4 years.

In the vaccine group there were 9 seizure events reported, compared to 1 in the placebo group, resulting in an odds ratio of 2.70  (95% confidence interval [CI], 0.76 to 9.57) during the 28 days following vaccination.

When analyzing the entire study periods included in the analysis (median time 43 days), the authors reported no significant difference between the vaccine and placebo groups in terms of incident new-onset seizure (13/43,724 events [0.03%] in vaccine and 5/40 612 [0.012%] in placebo recipients; odds ratio 2.31; 95% CI, 0.86 to 3.23).

“The findings suggest that there is no difference in risk of seizure incidence among vaccinated individuals vs placebo recipients,” the authors concluded. “However, the risk of seizure occurrence after SARS-CoV-2 infection seems to be relatively high.”