A COMPARISON OF ALTERNATE IMMUNIZATION REGIMES FOR MEASLES IN VACCINATED POPULATIONS

Infants today lose maternal measles antibody sooner than in the past. This is related to demographic changes in maternal immunization. Data for rates of decay of maternal antibody and seroconversion after measl es vaccination for infants born to naturally immune (Group 1) or vacci nated (Group 2) mothers have been used to evaluate two vaccination sch edules: Regime 1, measles-mumps-rubella (MMR) at 1 year of age and Reg ime 2, monovalent measles at 6 months followed by MMR at 15 months of age. Regime 2 costs less because MMR can be administered at 15 months with the last pentavalent booster. Months of protection/1000 children aged 0-15 months (child-months of protection) were estimated for infan t populations ranging from 0 to 100% Group 1 for Regimes 1 and 2. Regi me 1 provides more child-months of protection only for 100% Group 1 po pulations. For the study population Regime 2 provided at least 17% mor e child-months of protection than Regime 1. Regime 2 provides increase d medical and financial benefits in proportion to the number of Group 2 infants in the population and thus is ever more advantageous for tod ay's increasingly vaccinated populations. (C) 1998 Elsevier Science Lt d. All rights reserved.