mmr ii is supplied freeze-dried (lyophilized) and contains live viruses. before injection it is reconstituted with the solvent provided. according to a review published in 2018, the glaxosmithkline (gsk) mmr vaccine known as pluserix "contains the schwarz measles virus, the jeryl lynn–like mumps strain, and ra27/3 rubella virus". pluserix was introduced in hungary in 1999. enders' edmonston strain has been used since 1999 in hungary in merck mmr ii product. gsk priorix vaccine, which uses attenuated schwarz measles, was introduced in hungary in 2003. mmrv vaccine main article: mmrv vaccine the mmrv vaccine, a combined measles, mumps, rubella and varicella (chickenpox) vaccine, has been proposed as a replacement for the mmr vaccine to simplify administration of the vaccines. preliminary data indicate a rate of febrile seizures of 9 per 10,000 vaccinations with mmrv, as opposed to 4 per 10,000 for separate mmr and varicella shots; us health officials therefore do not express a preference for use of mmrv vaccine over separate injections. in a 2012 study pediatricians and family doctors were sent a survey to gauge their awareness of the increased risk of febrile seizures (fever fits) in the mmrv. 74% of family doctors and 29% of pediatricians were unaware of the increased risk of febrile seizures. after reading an informational statement only 7% of family doctors and 20% of pediatricians would recommend the mmrv for a healthy 12- to 15-month-old child. the factor that was reported as the "most important" deciding factor in recommending the mmrv over the mmr+v was acip/aafp/aap recommendations (pediatricians, 77%; family physicians, 73%). mr vaccine this is a vaccine that covers measles and rubella but not mumps. as of 2014, it was used in a "few (unidentified) countries". society and culture religious concerns some brands of the vaccine use gelatin, derived from pigs, as a stabilizer. this has caused reduced take-up among some communities, despite the fact that alternative vaccines without pig derivatives are approved and available.