Can vaccines cause seizures?

Unfortunately, they sometimes can.

Vaccines and Febrile Seizures

The CDC reports that “There is a small increased risk for febrile seizures after MMR and MMRV vaccines.”

We also know that:

• there is a small increased risk for febrile seizures when the influenza vaccine is given at the same time as either the Prevnar13 vaccine or the DTaP vaccine, although “the risk of febrile seizure with any combination of these vaccines is small and CDC’s Advisory Committee on Immunization Practices (ACIP) does not recommend getting any of these vaccines on separate days.”
• there is a small increased risk for febrile seizures if the combined MMR and chicken pox vaccine (ProQuad) is given to infants between the ages of 12 to 23 months vs their getting the shots separately.

But remember that febrile seizures, while scary for parents and other caregivers, are rarely dangerous.

It is also important to note that while febrile seizures are common, they are not commonly triggered by vaccines. A 2016 report in Pediatrics, “Vaccines and Febrile Seizures: Quantifying the Risk,” states that “The risk is 1 febrile seizure per pediatric practice every 5 to 10 years.”

Not surprisingly though, vaccines can likely prevent many febrile seizures, as chicken pox, flu, Hib, measles, mumps, rubella, pneumococcal infections and other vaccine-preventable diseases often cause fever and can trigger febrile seizures themselves.

Also, a study recently found that children who got sick with pertussis could be at increased risk for developing epilepsy, or recurrent seizures. That’s just another good reason to get vaccinated and protected against vaccine-preventable diseases.

Vaccines and Other Types of Seizures

While vaccines can sometimes trigger febrile seizures, they do not typically cause other types of seizures.

It was once thought that seizures were a common side effect of the DPT vaccine, but many studies have found that to not be true and seizures following DPT was even removed as a table injury from the NVICP. In fact, many of these children were instead found to have Dravet syndrome, which put them at increased risk for febrile seizures.

Long-term non-febrile seizures are still listed as side effects for the DTaP and MMR vaccine, but they “are so rare it is hard to tell if they are caused by the vaccine.”

A 2010 study in Pediatrics, “Lack of Association Between Acellular Pertussis Vaccine and Seizures in Early Childhood,” did not find any “increased risk for seizures after
DTaP vaccination among children who were aged 6 weeks to 23 months.”

Do report any reaction to VAERS if you think it was caused by a vaccine though.

Seizures After Getting Vaccines

If vaccines don’t usually cause seizures, then how do you explain a healthy infant developing seizures a few days, weeks, or months after getting his vaccines?

We’re always looking for reasons why something happened. The example I use is from my wife, who is a pediatrician. She was about to vaccinate a four-month-old baby, and while she was drawing the vaccine from the syringe, the baby had a seizure — and went onto have a permanent seizure disorder. Now, my wife hadn’t given the vaccine yet. But if she had given that vaccine five minutes earlier, there would have been no amount of statistical data in the world that would have convinced that mother that the vaccine hadn’t caused the baby’s seizure. You can do studies that show no increased risk with vaccines and seizure disorders, but that mother might still say “well, that’s true for the population but it’s not true for my child.”

Temporal associations are powerful, and they’re hard to defeat with statistics or studies.

Paul Offit, MD interview for The Thinking Persons Guide to Autism

There are many seizure disorders that begin in infancy.

Some even start in the newborn period, before a baby is a month old.

They are not triggered by vaccines though.

They include:

• Infantile Spasms (first described in 1841) – typically begin when infants are about 4 months old, just when they get their second set of vaccines, which weren’t available when Dr. West described his own son’s repeated spasms
• Benign Familial Neonatal Seizures – often genetic, seizures may begin on a baby’s third day of life
• Benign Neonatal Convulsions – begin on the fifth day of life – the “fifth day fits,” and the seizures stop in about a month

If your child got her first hepatitis B vaccine when she was five days old and began having seizures, would you accept a diagnosis of Benign Neonatal Convulsions or would you blame the shot?

Would you remember the saying about correlation and causation?

For More Information on Vaccines and Seizures:

• MMRV and Febrile Seizures
• What Clinicians Need to Know About MMRV Vaccine Safety
• Childhood Vaccines and Febrile Seizures
• Febrile Seizures Following Childhood Vaccinations, Including Influenza Vaccination
• Ask the Experts about Pertussis Vaccines (DTaP, Tdap)
• CDC – Possible Side-effects from Vaccines
• A Family Struggles to Understand Seizures Following Vaccination
• A Parent’s Story of Vaccine Reaction
• Febrile Seizures
• Surprise Link Between Epilepsy And Whooping Cough: What’s The Connection?
• Infantile Spasms / West’s Syndrome
• Dravet syndrome
• Dravet syndrome is not a vaccine induced genetic mutation