From the Guidelines
Measles Antibody Titers in Adults
Measles titers are typically considered protective if they are greater than or equal to 1:10 1.
- If an adult's measles titer is less than 1:10, or if the titer is unknown, the Centers for Disease Control and Prevention (CDC) recommends administering 2 doses of the measles, mumps, and rubella (MMR) vaccine, separated by at least 28 days, to ensure adequate immunity.
- Adults born before 1957 are generally considered immune to measles and mumps 1.
- A routine second dose of MMR vaccine is recommended for adults who are students in postsecondary educational institutions, work in a health-care facility, or plan to travel internationally 1.
- Key Points:
- Measles titers ≥ 1:10 are considered protective.
- Adults with unknown or low measles titers should receive 2 doses of MMR vaccine.
- Certain groups, such as healthcare workers and international travelers, may require a second dose of MMR vaccine.
- Adults born before 1957 are generally considered immune to measles and mumps.
From the Research
Measles Antibody Titers in Adults
- The measles-neutralizing antibody titers in adults can vary depending on the number of vaccine doses received and the time elapsed since vaccination 2, 3, 4.
- A study found that among adults who received one or two doses of the measles-mumps-rubella (MMR) vaccine, 45.8% had a medium (121−900) or high (>900) plaque reduction neutralization (PRN) titer after 2 years 2.
- Another study showed that 26-33 years after vaccination, 92% of adults had a PRN titer considered protective (>1 : 120) 3.
- A longitudinal study found that approximately 5 and 9-11 years after receipt of a third MMR dose, the geometric mean concentrations (GMCs) of measles antibody were 428 mIU/mL and 381 mIU/mL, respectively 4.
- The protective titers of measles neutralizing antibody have been defined as >1,000 mIU/ml to prevent measles infection and >500 mIU/ml to prevent symptomatic infection 5.
Factors Influencing Measles Antibody Titers
- The number of vaccine doses received can influence measles antibody titers, with three doses providing higher and more sustained antibody levels 4.
- The time elapsed since vaccination can also affect measles antibody titers, with a decline in antibody levels over time 2, 3, 4.
- Birth date prior to 1972 has been correlated with a need for measles revaccination in adolescents, due to differences in vaccination schedules and maternal antibody levels 6.