Between 2001 and 2011, the average number of measles cases reported in the United States per year was 62. There were 644 reported cases of measles in 2014 — the highest number of cases since 2000. This year, there have already been 102 reported cases across 14 states, making the number of cases so far in 2015 higher than the number of cases the U.S. typically sees in an entire year. The outbreak that originated at Disneyland represents 92 percent of the reported cases this year.
According to the Centers for Disease Control, before the live measles vaccine was introduced in 1963, the average number of cases per year was 549,000. After the one-shot vaccine was introduced, the number of measles cases dropped significantly. There was a resurgence of the disease from 1989 to 1991, during which 55,000 people were affected. Although most were unvaccinated, some people with the vaccine also got the disease, leading the medical community to recommend the two dose regimen. Since that regimen was introduced, measles cases have been dramatically reduced, leading the U.S. to declare in 2000 that endemic measles were "eliminated."
In other words, if your child is vaccinated, you do not need to be concerned. Dr. Anne Schuchat, assistant surgeon general and director of the CDC's National Center for Immunization and Respiratory Diseases, says, "This is not a problem with the measles vaccine not working. This is a problem of the measles vaccine not being used."