Why are two doses of MMR required for birth before 1957?
During normal times one dose may be enough to provide immunity. However unlike measles, you cannot assume those born before 1957 are immune to mumps. Iowa is experiencing a wide-spread mumps outbreak (over 150 cases, with no signs of slowing). Therefore the health care setting is a high risk setting for spread to HCW and spread to vulnerable patients. Thus IDPH is recommending the best possible protection both for the HCW and their patients… two doses. This is not a requirement from the health department, just a strong recommendation. The recommendations were review with experts at CDC, and IDPH Advisory Committee, and they are in agreement. Live mumps vaccine was not used routinely before 1977, and the peak incidence of disease was among 5 to 9 year olds before the vaccine was introduced. Most people born before 1957 are likely to have been infected naturally between 1957 and 1977. As a result, persons born before 1957 generally may be considered to be immune, even if they did not h
