How Many Doses of MMR Would You Give?
Sample: How many MMR doses should a 4-month-old travelling to Italy next month with family receive? Plus 4 more patient scenarios.
Just prior to the COVID-19 pandemic, the Centers for Disease Control and Prevention (CDC) reported nearly 1100 cases of measles in 30 states. This is the greatest number of cases reported in the US since 1992, with the majority of cases being among people who were not vaccinated.
Given the decline in uptake of routine vaccination during the Public Health Emergency triggered by the pandemic, patients may now have questions about whether they or their children are still protected from measles. Per CDC guidelines, some may not need any doses of MMR and some may need 1, 2, or 3 doses.
Click through the slides below for 5 patient scenarios and how many shots are needed in each case.
Review these 5 patient scenarios. Can you match each with the correct MMR dose? Click through the rest of the slides for the answers.
Scenario 1. Needs 1 dose. The patient in scenario 1 would be considered a “low risk” case and should receive 1 dose of MMR. Persons considered at high risk would include healthcare workers, persons in colleges and universities, and international travelers. Persons at high risk should receive 2 doses.
Scenario 2. Needs 1 dose. The physician in scenario 2 is an exception to the rule that people born before 1957 can be considered immune due to the local measles outbreak. Healthcare workers born before 1957 without laboratory evidence of immunity should receive 1 dose if in an area with a measles outbreak.
Scenario 3. Does not need a dose. The physician in scenario 3 does not need an MMR vaccination; he was born before 1957 and is in a low-risk environment. The CDC says one should "consider" giving a healthcare worker born before 1957 with no evidence of protection a single dose of MMR to protect against measles (but would need 2 doses for rubella and mumps protection if not immune to those diseases). The CDC says one "should" give 2 doses during an outbreak of measles.
Scenario 4. Does not need a dose. The 4-month-old infant in scenario 4 should not receive a dose of MMR until at least 6 months of age. He most likely is immune due to transferred maternal measles antibodies.
Scenario 5. Needs 3 doses. The 7-month-old infant in scenario 5 will end up receiving 3 doses of MMR. Infants aged 6-12 months should receive 1 dose of MMR 2 weeks before any international travel. The infant will then need 2 doses after 12 months of age. MMR vaccine given before 12 months of age may not result in an adequate immune response due to the presence of maternal antibody.
Please note: Part 2 with 5 more patient scenarios will be available shortly.
References:
1. Centers for Disease Control and Prevention. Prevention of measles, rubella, congenital rubella syndrome, and mumps, 2013: summary recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR. 2013;62:1-34.
2. Centers for Disease Control and Prevention. Measles. In: Hamborsky J, Kroger A, Wolfe S, eds. Epidemiology and Prevention of Vaccine-Preventable Diseases. Washington, D.C. Public Health Foundation; 2015:209-229.
