How effective is the MMR vaccine in general?
The MMR vaccine is very effective against measles, mumps, and rubella and has made these three once-common childhood diseases very rare in the United States. Before there was a vaccine against mumps, mumps was a common disease in the United States and caused complications such as permanent deafness in children, and it occasionally caused encephalitis, which can result in death, although very rarely. Before vaccine was used, over 150,000 mumps cases were reported every year, although many more unreported cases occurred. Now, a few hundred cases of mumps are reported every year on average. However, outbreaks still occasionally occur. In 2006, there was an outbreak affecting more than 6,584 people in the United States, with many cases occurring on college campuses. In 2009, an outbreak started in close-knit religious communities and schools in the Northeast, resulting in more than 3,000 cases. These outbreaks have shown that when people who are sick with mumps have close contact with a lo
