Serologic responses to measles, mumps, and rubella (MMR) vaccine in healthy infants: Failure to respond to measles and mumps components may influence decisions on timing of the second dose of MMR

Leslie Ann Mitchell PhD,1,2 Aubrey J. Tingle, MD, PhD,1 Diane Decarie, BSc,1 Carol Lajeunesse, BScN2

A B S T R A C T

Measles, mumps, and rubella-specific IgG antibodies were evaluated in 134 healthy infants routinely immunized with trivalent live attenuated measles-mumps-rubella (MMR) vaccine at one year of age. Blood samples were collected just before, and at 1, 3, and 12 months after MMR. Specific IgG was measured by commercial enzyme immunoassays. Before vaccination, 98.5%, 99.2%, and 98.5% of the infants tested were seronegative for measles, mumps, and rubella, respectively. One year after MMR, 16.4% and 22.4% of vaccinees lacked demonstrable antibody to measles and …