Risk of febrile seizures after first dose of measles–mumps–rubella–varicella vaccine: a population-based cohort study

Safety of Measles-Containing Vaccines in 1-Year-Old Children

“…This study further confirmed (by using previously unanalyzed data) that MMRV and MMR + V are both associated with fever and seizure 7 to 10 days after vaccination, and validated our previous findings and those of others that MMRV versus MMR + V is associated with an excess risk of seizures 7 to 10 days after vaccination. 19,20,[34][35][36] This study replicated previously reported safety findings, which provides additional reassurance that assessing the 7 main outcomes with this approach was reasonable.…”

Combination measles–mumps–rubella–varicella vaccination and the risk of febrile seizure

“…Of note, in children with a history of seizure or a seizure disorder, there was no difference in risk between the MMRV and MMR+V vaccines (relative risk 1.30, 95% CI 0.60-2.79). 2 These findings are similar to those of population-based cohort studies conducted in the United States with a different MMRV formulation, ProQuad (Merck), which showed an excess risk of one febrile seizure per about 2300-2600 doses of MMRV, compared with separate MMR+V vaccines. 4,6 MacDonald and colleagues' 2 study is the first in Canada, and the largest study to date to assess this risk with the Priorix-Tetra formulation of MMRV.…”

Immunogenicity and safety of a combined measles, mumps, rubella and varicella live vaccine (ProQuad®) administered concomitantly with a booster dose of a hexavalent vaccine in 12–23-month-old infants

“…the first but not the second doses of MMRV combined vaccines compared with separate MMR and varicella vaccines [24][25][26][27]. The data on a first dose of ProQuad ® observed in this study are still applicable with the hexavalent booster vaccine administered concomitantly with a second dose of ProQuad ® later in life.…”