Seizures are spasms that are common in some conditions such as epilepsy. Seizures can often also happen when a person has a fever - called a "febrile" fever.
Febrile fevers are relatively common in children, with up to 5% of children having a febrile seizure at some point. This does not seem to occur commonly in adults.
Sometimes vaccines can cause fevers, so it makes sense that if a fever can be caused by vaccines that the vaccine-caused fever carries a risk of febrile seizure.
Studies have specifically shown that there is a small increased risk in febrile seizures soon after a child has received their first measles, mumps, rubella (or MMR) vaccination. A small increased risk has also been found when a child gets the seasonal flu vaccine at the same doctor visit as either the PCV13 or DTaP vaccine. Usually, these fevers occur within days after the vaccine, and there does not seem to be any lasting effects or recurrent seizures from these vaccine-related febrile seizures.
Some research shows that some children who suffered a post-vaccine febrile seizure had an undiagnosed, pre-existing condition prior to vaccination which increased their risk. However, that research seems to show that though the vaccines may have triggers a child's first seizures, the underlying condition was the cause.
If your child suffers a seizure after a vaccine, you may be eligible for compensation. Contact an attorney familiar with the Vaccine Injury Compensation Program (VICP) to find out.