The combined measles-mumps-rubella-varicella (MMRV) vaccine shows a slightly increased risk of febrile seizures in children, compared with the previously separate vaccines for MMR and varicella (chickenpox) (MMR+V), according to an article in CMAJ (Canadian Medical Association Journal).
The combined measles–mumps–rubella–varicella (MMRV) vaccine shows a slightly increased risk of febrile seizures in children, compared with the previously separate vaccines for MMR and varicella (chickenpox).
watching your child in pain is really very scary for parents and just imagining your child experiencing a febrile seizure, which commonly includes losing consciousness and shaking is very frightening.
According to research one in every 25 children has at least one febrile seizure at some point, while more than a third of these children will have additional febrile seizures before they outgrow the tendency.
Commonly, the seizures occur between the ages of 6 months and 5 years. Although distressing to parents, febrile seizures are not associated with any ongoing health issues.
Now, new research from Canada has shown how the combined measles–mumps–rubella–varicella (commonly referred to as the MMRV) vaccine shows a slightly increased risk of febrile seizures in children, compared with the previously separate vaccines for MMR and varicella (chickenpox).
“Potential benefits must be balanced by the increased risk (albeit small) of febrile seizures with the combination vaccine,”
wrote the authors in their study published today in the Canadian Medical Association Journal.
Initially, the MMRV vaccine was developed for young children to reduce the number of needles they receive. However, the combined vaccine has been associated with slightly higher rates of febrile seizures.
Combining MMR and varicella into a single vaccine decreases pain for children and distress for parents, thus addressing common barriers to vaccine uptake, and may improve vaccination coverage levels and decrease immunization delivery costs,”
writes Dr. Shannon MacDonald, Faculty of Medicine, University of Calgary.
“Febrile seizures are typically self-limiting and rarely have long-term effects, but they can be extremely distressing for parents, may precipitate acute care visits, and may undermine confidence in immunization programs.”
Currently, two vaccines, with different formulations, are available in North America: ProQuad (Merck) is used primarily in the U.S., whereas Priorix-Tetra (GlaxoSmithKline) is primarily used in Canada.
Vaccine safety studies of ProQuad have identified a slightly increased risk of febrile seizures in children after the first dose (given between the ages of 12 to 23 months), but not after the subsequent preschool dose.
Similarly, studies of Priorix-Tetra have found it to be as safe as the two separate vaccines, except for a higher incidence of fever.
Researchers looked at data on 227,774 children between the ages of 12 and 23 months who had received either the MMRV vaccine or the MMR plus to determine whether there is an increased risk of febrile seizures from the combined vaccine a separate chickenpox vaccine between 2006 and 2012 in Alberta, Canada.
After analyzing the data, the researchers found a slight increase in the relative risk of febrile seizure with the MMRV vaccine compared with the MMR+V vaccine — about one excess seizure for every 2,841 doses.
The researchers noted that, although this rate is double that of the two separate vaccines, the absolute risk is relatively small. Plus, their findings are consistent with the results of a study of the U.S. version of the vaccine.
For these two reasons, they suggest counseling parents about the risk of fever and, when necessary, recommending fever medication to alleviate any symptoms.
Source: MacDonald SE, Dover DC, Simmonds KA, Svenson LW. Risk of febrile seizures after the first dose of measles–mumps–rubella–varicella vaccine: a population-based cohort study. Canadian Medical Association Journal. 2014