Vaccines Associated with Seizures
The pertussis-containing vaccines (DTP, DTaP, and Tdap) are the primary vaccines associated with increased seizure risk, particularly in children with a personal or family history of seizures, though these seizures are typically febrile, self-limited, and do not cause permanent neurological damage. 1
Pertussis-Containing Vaccines (Highest Risk)
DTP (whole-cell) and DTaP (acellular) vaccines carry the most well-documented seizure risk:
- Children with prior seizures (febrile or afebrile) have an increased risk of seizures within 3 days following DTP/DTaP vaccination compared to children without seizure histories 1
- The seizures are typically triggered by vaccine-induced fever in children prone to febrile seizures or may be directly induced by the pertussis component 1
- Current evidence indicates these post-vaccination seizures do not cause permanent brain damage 1
- DTaP is preferred over whole-cell DTP for children with seizure histories because it causes less fever 1
Management Strategy for Pertussis Vaccination in Seizure-Prone Children:
- Delay vaccination until neurologic status is fully assessed, treatment regimen established, and condition stabilized 1
- Children with stable neurologic conditions, including well-controlled seizures, may be vaccinated with DTaP 1, 2
- Administer acetaminophen 15 mg/kg at vaccination time and every 4 hours for 24 hours to reduce fever risk 1, 3
- A family history of seizures (affecting 5-7% of children) is NOT a contraindication to pertussis vaccination, though prophylactic acetaminophen should be given 1
MMR Vaccine (Moderate Risk)
MMR vaccination causes febrile seizures at a rate of approximately 1 per 3,000 doses:
- Febrile seizures occur 5-14 days after MMR vaccination, coinciding with vaccine-induced fever 1
- Children with personal or family history of seizures have a minimally increased risk, but the benefits substantially outweigh risks and vaccination should proceed 1
- Studies have not established an association between MMR vaccination and residual seizure disorders 1
- Most post-MMR convulsions are simple febrile seizures with benign outcomes 1
Key Caveat:
Parents should be counseled about fever monitoring 5-14 days post-vaccination, as fever onset is often sudden and unpredictable, making prophylactic antipyretics difficult to time effectively 1
COVID-19 Vaccines (Minimal Risk)
Recent high-quality evidence shows COVID-19 vaccines do not significantly increase seizure risk:
- A 2024 meta-analysis of 13 million vaccinated versus 13 million unvaccinated individuals found no statistically significant difference in new-onset seizure incidence (OR = 0.48,95% CI 0.19-1.20) 4
- Among persons with epilepsy (PWE), only 2.5-5% experience seizure exacerbation post-vaccination, primarily those with ongoing uncontrolled seizures 5, 6
- No difference in seizure risk between mRNA and viral vector vaccines 6
- Status epilepticus occurs in only 0.08% of PWE post-vaccination 6
Important Context:
Seizure worsening after COVID-19 vaccination in PWE is more strongly associated with improper antiseizure medication administration and disrupted sleep routines than the vaccine itself 7
Contraindications vs. Precautions
Absolute contraindications to pertussis-containing vaccines:
- Encephalopathy within 7 days of previous pertussis-containing vaccine dose 2
- Anaphylaxis to previous dose or vaccine component 2
Defer vaccination (not contraindicated) when:
- Unstable or progressive neurologic disorder present—use DT instead of DTaP until stabilized 1, 2
- Guillain-Barré syndrome within 6 weeks of previous tetanus-containing vaccine requires risk-benefit assessment 2
Clinical Bottom Line
The risk of seizures from pertussis disease itself far exceeds the risk from pertussis vaccination, particularly in neurologically disabled children who may experience anoxia and intracerebral hemorrhages from the disease 1. Similarly, COVID-19 infection complications in PWE substantially outweigh vaccination-related seizure risks 5.