To determine whether there is an increased risk of
febrile seizures from the combined vaccine, researchers looked at data on 227 774 children aged 12 to 23 months who received either the MMR+V or the MMRV vaccine
between 2006 and 2012 in Alberta, Canada.
This study included
febrile children presenting to participating hospitals in the United Kingdom, Spain, the Netherlands, and the United States
between 2009 - 2013, and placed in a discovery group or validation group.