Combination vaccine linked to febrile seizures

Two separate unpublished studies have confirmed an association between the first dose of the combination MMR-Varicella (MMRV) vaccine and an increased risk of febrile seizures.

The MMRV vaccine is called ProQuad and is manufactured by Merck. One of the studies was sponsored by Merck, and the other was done by the Centers for Disease Control (CDC) in what is known as the Vaccine Safety Datalink (VSD) Project. The CDC safety study among children aged 12 to 23 months detected a cluster of cases of febrile seizure seven to 10 days after vaccination.

The CDC addresses questions related to CDC study on the combined measles, mumps, rubella, and varicella (MMRV) vaccine and febrile seizures here..

Often parents and pediatricians favor combination vaccines instead of separate vaccines to avoid multiple needle sticks. However, this quadruple vaccine injects a load of four different live viruses as well as other preservative materials and there is an increased level of fever in response, which is the simplest explanation for the increase in seizures. However, according to the research and as explained on the Food and Drug Administation (FDA) website ”the interim analysis of Merck’s post-marketing study showed that febrile seizures occurred more frequently 5 to 12 days following vaccination of approximately 14,000 children with ProQuad (0.5 per 1,000) when compared with a historical, age and sex-matched control group vaccinated with MMR and varicella vaccines administered separately at the same visit.“

Because of manufacturing difficulties, the MMRV shot has not been readily available until this year, so you might not have been offered it until now. If your pediatrician recommends this quadruple vaccine for your infant, what will your response be?

Photo:CDC

http://blogs.parentcenter.babycenter.com/momformation/2009/01/21/combination-vaccine-linked-to-febrile-seizures/