Measles-containing vaccines not linked with increased risk of febrile seizures in kids 4-6
“While this earlier study and the resulting CDC recommendations are very important and ones our pediatricians follow, it is also important to emphasize that it is more common for a child to have a febrile seizure caused by a simple cold than by an immunization. And though febrile seizures are a very scary event for a family, they are not dangerous and do not lead to later epilepsy or seizure disorders,” said Randy Bergen, MD, a Kaiser Permanente pediatrician and infectious disease specialist at Kaiser Permanente Walnut Creek Medical Center.
What are febrile seizures?
Febrile seizures are convulsions brought on by a fever in infants or small children. During a febrile seizure, a child often loses consciousness and shakes, moving limbs on both sides of the body. Less commonly, the child becomes rigid or has twitches in only a portion of the body, such as an arm or a leg, or on the right or the left side only. Most febrile seizures last a minute or two, although some can be as brief as a few seconds while others last for more than 15 minutes.
The majority of children with febrile seizures have rectal temperatures greater than 102 degrees Fahrenheit. Most febrile seizures occur during the first day of a child’s fever. Children prone to febrile seizures are not considered to have epilepsy, since epilepsy is characterized by recurrent seizures that are not triggered by fever.
What makes a child prone to recurrent febrile seizures?
A few factors appear to boost a child’s risk of having recurrent febrile seizures, including young age (less than 15 months) during the first seizure, frequent fevers, and having immediate family members with a history of febrile seizures. If the seizure occurs soon after a fever has begun or when the temperature is relatively low, the risk of recurrence is higher. A long initial febrile seizure does not substantially boost the risk of recurrent febrile seizures, either brief or long.
The Vaccine Safety Datalink project is a collaborative effort among CDC’s Immunization Safety Office and eight managed care organizations: Kaiser Permanente Northern California, Kaiser Permanente Southern California, Kaiser Permanente Colorado, Kaiser Permanente Northwest, Health Partners (Minn.), Group Health Cooperative (Wash.), Marshfield Clinic (Wisc.) and Harvard Pilgrim Health Care (Mass.). The VSD project was established in 1990 to monitor immunization safety and address the gaps in scientific knowledge about rare and serious events following immunization. The VSD shares electronic health records from the organizations’ health systems.
MMRV was licensed by the FDA in 2005 and subsequently recommended by the Advisory Committee on Immunization Practices in 2006. Although pre-licensure studies of MMRV among 1-2 year olds noted higher rates of fever and measles-like rash one to two weeks post vaccination when compared with separate MMR+V, it was unknown at the time of MMRV’s licensure whether a higher rate of fevers was similarly associated with increased risk of febrile seizures. In February 2008, Kaiser Permanente researchers alerted the CDC’s Advisory Committee on Immunization Practices to preliminary evidence of an increased risk of febrile seizures following MMRV for 1-2 year olds, findings which were subsequently confirmed in the 2010 study published in Pediatrics.
“The Vaccine Safety Datalink - which we used to conduct both the study of 1-2 year olds and the study of 4-6 year olds, is a premier example of how different managed care organizations can leverage their electronic medical records to improve vaccine safety and monitoring,” Klein said.
###
Additional authors on this paper include: Edwin Lewis, MPH, from the Kaiser Permanente Vaccine Study Center; Roger Baxter, MD, from the Kaiser Permanente Vaccine Study Center; Eric Weintraub, MPH, from the Vaccine Safety Datalink; Jason Glanz, PhD, from Kaiser Permanente Colorado; Allison Naleway, PhD, Kaiser Permanente, Portland, Ore.; Lisa Jackson, MD, PhD, from Group Health Cooperative; James Nordin, MD, MPA, from Health Partners Research Foundation, Minneapolis; Tracy Lieu, MD, MPH, from Harvard Pilgrim Health Care Institute; Edward A. Belongia, MD, from Marshfield Clinic Research Foundation; and Bruce Fireman, MA, from the Kaiser Permanente Vaccine Study Center.
About the Kaiser Permanente Northern California Division of Research
The Kaiser Permanente Division of Research conducts, publishes and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and the society at large. It seeks to understand the determinants of illness and well-being and to improve the quality and cost-effectiveness of health care. Currently, DOR’s 400-plus staff is working on more than 250 epidemiological and health services research projects.
About Kaiser Permanente
Kaiser Permanente is committed to helping shape the future of health care. We are recognized as one of America’s leading health care providers and not-for-profit health plans. Founded in 1945, our mission is to provide high-quality, affordable health care services and to improve the health of our members and the communities we serve. We currently serve approximately 8.9 million members in nine states and the District of Columbia. Care for members and patients is focused on their total health and guided by their personal physicians, specialists and team of caregivers. Our expert and caring medical teams are empowered and supported by industry-leading technology advances and tools for health promotion, disease prevention, state-of-the art care delivery and world-class chronic disease management. Kaiser Permanente is dedicated to care innovations, clinical research, health education and the support of community health.
###
Danielle Cass
.(JavaScript must be enabled to view this email address)
510-267-5354
Kaiser Permanente