Despite effective vaccination programs for measles, mumps, and rubella in the United States and Canada, outbreaks continue to occur in susceptible subgroups, such as foreign-born persons.
Greenaway C, Dongier P, Boivin JF, Tapiero B, Miller M, Schwartzman K. Ann Intern Med. 2007 Jan 2;146(1):20-4. doi: 10.7326/0003-4819-146-1-200701020-00005. PMID: 17200218