Long-term immunity to measles, mumps and rubella after MMR vaccination among children with bone marrow transplants.

Measles, mumps and rubella (MMR) vaccine-induced long-term immunity was studied in 30 children with bone marrow transplants (BMT). Immunity at baseline for MMR was 13.3, 33.3 and 66.6%, respectively. MMR vaccination failed to induce adequate and persistent responses to measles and mumps; seropositivity at 1 and 12 months for measles was 26.6 and 23.3% and for mumps 46.6 and 36.6%, respectively. In contrast, 27 of 30 children with a BMT were immune to rubella 1 month after immunization and retained protective antibody levels at 12 months. The MMR-induced anamnestic responses to rubella among all responders were associated with the production of high avidity antibodies. We conclude that a single dose of MMR given at 2 years after BMT induces suboptimal and short-lived immune responses to measles and mumps; a second dose should be recommended for paediatric BMT recipients.