The combined measles-mumps-rubella-varicella (MMRV) vaccine could raise the risk of seizures in toddlers when compared with separate vaccinations for MMR and the chicken pox (MMR+V) in Canada.

The combined MMRV vaccine was first developed to cut down on the amount of needles frightened children would need to endure, a Canadian Medical Association Journal  news release reported.

New research suggests this vaccine causes a higher rate of febrile seizures, but not ongoing health consequences.

"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," Doctor. Shannon MacDonald, Faculty of Medicine, University of Calgary, said in the news release. "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."

To make their findings researchers looked at cases of 227, 774 children who received MMR+V or the MMRV vaccine between 2006 and 2012 between the ages of 12 and 23 months.

The team found a rise in the relative risk of febrile seizure when between the MMRV vaccine was compared to the MMR+V. There was about one excess seizure in every 2,841 administered does. This absolute risk is relatively small.

"It is a matter for debate whether the choice of separate versus combination vaccine is a policy decision or a choice for parents to make in consultation with their vaccination provider," the authors said, the news release reported.

The findings are believed to be consistent with the results of a study conducted on the U.S. version of the vaccine.

"Two versions of MMRV are used in North America. Canada uses the Priorix-Tetra formulation, as does Australia, Italy and Germany; the United States uses ProQuad. Priorix-Tetra is also approved for use in many member states of the European Union," the news release reported.