Because MMRV bundles the chickenpox vaccine, it means children can get away with one less shot over the course of their vaccinations — and that can be a big deal for the needle-adverse.
The MMRV, however, does come with an increased risk of fevers: Roughly 22 out of every 100 children will run a fever of 102 degrees or higher, post-vaccination, per the CDC. The MMR results in fevers in about 15 out of every 100 children.