The new combined MMRV (measles-mumps-rubella-varicella) vaccine doubles the risk of a fit, or febrile seizure, although the overall risk remains low, say researchers.
The febrile seizure risk with the standard MMR vaccine is around one case per 2,841 children vaccinated, and the new combined vaccine-which also includes the varicella, or chicken pox, component-doubles that risk.
In some cases, the children have been rushed to hospital emergency rooms, although long-term damage has been rare, say researchers from the University of Calgary.
Similar results have been seen by American researchers, and parents will need to think carefully before deciding on the vaccination for their child. The risk may also put some parents off from giving their child any vaccine, the researchers add.
(Source: CMAJ, 2014: doi: 10.1503/cmaj.140078)
