There is a slight risk for seizure worsening following SARS-CoV-2 mRNA vaccinations, however, no poor outcomes were reported after 6 months of follow-up in people with epilepsy.

Some people with epilepsy, particularly those with refractory focal epilepsy, exhibit seizure exacerbations following administration of a SARS-CoV-2 mRNA vaccine, with the risk for worsening particularly prominent within a few days of vaccination. However, after 6 months of follow-up, there were no cases with poor outcomes. These are the findings of a study published in the journal Epilepsy & Behavior.

Researchers sought to evaluate seizure outcomes among people with epilepsy following COVID-19 mRNA vaccination. The multicenter study was conducted among individuals with epilepsy who visited an epilepsy center in the Division of Neurology at 1 of 4 tertiary care hospitals in Japan (Hiroshima University Hospital, Hiroshima City Asa Citizens Hospital, Hiroshima City Hiroshima Citizens Hospital, and Hiroshima City Funairi Citizens Hospital, which encompass a medical area with a population of >1 million). They aimed to identify clinical factors that were associated with seizure worsening and 6-month outcomes following vaccination.

To confirm the 6-month outcome of seizure following a first and second vaccination, the observation period used in the study was between April 2021 and March 2022. Further, a nationwide survey was conducted to identify the incidence of self-reported seizure exacerbations following vaccination. Study inclusion criteria were consecutive people with epilepsy whose medical history, including type of seizure and frequency of seizures, was available for all of the observation periods and whose vaccination history and 6-month outcomes from the time of vaccination were available.

A total of 332 consecutive people with epilepsy ≥14 years of age were enrolled in the study. Participants mean age was 36.4±17.2 years. Overall, 168 of the patients were male. The majority of the epilepsy classifications was focal, with the highest being temporal lobe epilepsy in 24.7% of individuals. The mean number of antiseizure medications currently being used was 1.8±1.2.

[T]he worsening events were infrequent, non-sustainable, and probably under-reported by PWE, suggesting that there is little evidence that worsening seizures discourage current and future vaccinations.

Among the study participants with epilepsy, 84.9% (282 of 332) of them were vaccinated, with 84.9% (282 of 332) having received the first dose of the vaccine, 84.3% (280 of 332) receiving the second dose, and 11.7% (39 of 332) receiving the third dose.

The main reasons for vaccine refusal among the people with epilepsy included low perceived benefit of vaccination, health concerns over an adverse reaction, information deficits regarding COVID-19, failure with scheduling, and low perceived risk for COVID-19 infection. None of these individuals, however, were concerned about experiencing seizure worsening after vaccination.

The researchers found that of the 282 people with epilepsy vaccinated in the 4 hospitals, 16 individuals exhibited seizure worsening. Most of the exacerbations occurred within 48 hours of vaccination and were not sustained, indicating that all people with epilepsy were at baseline condition at 6 months following vaccination. People with epilepsy with seizure worsening was more significantly associated with focal impaired awareness seizures, high frequency of seizures, and drug-resistant epilepsy at baseline, compared with individuals with epilepsy without seizure worsening.

Per multivariate regression analysis, focal impaired awareness seizures were independently associated with worsening (odds ratio, 7.0; 95% CI, 1.50-2.77).

Additionally, results of a nationwide survey of real-world data from 5156 people with epilepsy confirmed an extremely low rate of self-reported seizure worsening — that is, 0.43%.

The study included several limitations that warrant mention. When applying the data derived from this study to countries other than Japan, the epidemiologic difference regarding a smaller spread of COVID-19 infection in Japan compared with other countries should be taken into consideration. In Japan, the vaccination coverage rate as of December 3, 2021, was high — at 77% — compared with that in other countries. Further, since the study cohort was based on data from tertiary hospitals with epilepsy centers, the proportion of drug-resistant people with epilepsy might differ from that in general clinical practice.

The researchers highlighted that “[T]he worsening events were infrequent, non-sustainable, and probably under-reported by PWE, suggesting that there is little evidence that worsening seizures discourage current and future vaccinations.”

According to the researchers, they “find no reason to discourage vaccination in PWE, also in the future, when social conditions change and new vaccination is required.”



Source:, Shelia Jacobs