FACT SHEET: Childhood Vaccines and Febrile Seizures
What is a febrile seizure?
Sometimes, fevers can cause a person to experience spasms or jerky movements called seizures. These seizures related to fever are called febrile seizures.
Febrile seizures can occur with any illness that causes fever.
Febrile seizures can happen with any condition that causes a fever. Causes include common childhood illnesses like colds, the flu, an ear infection, or roseola. Vaccines sometimes cause fevers, but febrile seizures are rare after vaccination.
Infants and young children are most at risk for febrile seizures.
Up to 5% of young children will have at least one febrile seizure, usually associated with getting sick. Most febrile seizures happen in children between the ages of 6 months and 5 years. The most common age range to have a febrile seizure is 14–18 months. The recommended age for the first doses of MMRV, MMR, and varicella vaccines is 12-14 months old. During this time children in this age group are recommended to receive other routine vaccines as well.
Vaccines prevent many febrile seizures.
Getting a child vaccinated as soon as recommended prevents febrile seizures by protecting young children against measles, mumps, rubella, chickenpox, influenza, pneumococcal infections and other diseases that can cause fever and febrile seizures.
Febrile seizures are usually short.
During a febrile seizure, a child often has spasms or jerking movements and may lose consciousness. Febrile seizures usually last one or two minutes, and they do not cause any permanent neurological damage. They are most common with fevers of 102°F (38.9°C) or higher, but they can also happen at lower body temperatures or when a fever is going down.
Children recover quickly from febrile seizures.
Febrile seizures can be frightening, but nearly all children who have a febrile seizure recover quickly and are healthy afterwards. About 1 in 3 children who have one febrile seizure will have at least one more during childhood; some of these are linked to family health history. There is a small increased risk for febrile seizures after MMR and MMRV vaccines.
Studies have shown a small increased risk for febrile seizures during the first to second week after the first vaccination with measles, mumps, rubella (MMR) vaccine and the first dose of measles, mumps, rubella, and varicella (MMRV) vaccine. Studies have not shown an increased risk for febrile seizures after the acellular pertussis vaccine, DTaP, or after varicella (chickenpox) vaccine.
One vaccine called DTP (whole cell pertussis), which is no longer used in the United States, had a small increased risk for febrile seizures after DTP on the day the vaccine was given.
There is an increased risk for febrile seizures when influenza (flu) vaccine is given around the same time as PCV13 and DTaP vaccines.
A recent VSD study took a closer look at the 2010/2011 febrile seizure signal* for trivalent inactivated influenza vaccine (TIV or IIV) and pneumococcal 13-valent conjugate vaccine (PCV-13). The study included the 2006-2009 seasons in addition to the 2010-2011 influenza season. The findings showed that PCV and DTaP both increase risk of febrile seizure when given at the same time as the flu vaccine. CDC found that when TIV was given alone, it was not associated with an increased risk of febrile seizures (in the influenza seasons studied).
*A signal is a scientific “red flag,” alerting CDC that a vaccine may be causing a problem.
CDC and FDA closely monitor the safety of all vaccines.
CDC and the Food and Drug Administration (FDA) are committed to ensuring that vaccines provided to the public are safe and effective. Once vaccines are licensed in the United States, CDC actively monitors the safety of these vaccines through several systems. If any vaccine is found to cause health problems, the vaccine may be withdrawn and no longer given to the public.
Specific information about vaccine safety monitoring efforts can be found at: http://www.cdc.gov/vaccinesafety/Vaccine_Monitoring/Index.html.
Can febrile seizures after any childhood vaccination be reported to CDC and FDA?
The National Childhood Vaccine Injury Act (NCVIA) requires healthcare providers to report any adverse event that is listed by the vaccine manufacturer as being a contraindication (reason for not giving the child any further doses of the vaccine). The NCVIA also requires healthcare providers to report any adverse event that is listed in the Vaccine Adverse Event Reporting System (VAERS) Table of Reportable Events Following Vaccination [PDF - 75 KB] if that event occurs within a specified time period after the child is vaccinated.
Healthcare providers are encouraged to report other clinically significant adverse events that follow immunization to VAERS even if they are unsure whether the event was caused by vaccine.
There are three ways to report events to VAERS:
- Submit an online form via a secure website at https://vaers.hhs.gov/esub/step1;
- Fax a completed VAERS form to 877-721-0366; or
- Mail a completed VAERS form to VAERS, P.O. Box 1100, Rockville, MD 20849-1100.
A VAERS form may be downloaded from the VAERS website at http://vaers.hhs.gov/resources/vaers_form.pdf. A VAERS form may also be requested by sending an e-mail to email@example.com, by calling toll-free 800-822-7967, or by sending a faxed request to 877-721-0366. For additional information on VAERS or vaccine safety, visit the VAERS website at www.vaers.hhs.gov or call 800-822-7967.
Where can I learn more about febrile seizures?
To learn more about febrile seizures, visit the following sites:
- The National Institutes of Health (NIH), National Institute of Neurological Disorders and Stroke Febrile Seizures Information Page
- The American Academy of Pediatrics healthy children website, which offers additional information about febrile seizures.