individual analysis showed that following immunization antibody titers reached 0.15 micrograms/ml or more in 65 % of infants aged 15 to 17 months , 71 % of infants aged 18 to 23 months , 80 % of infants aged 24 to 30 months and 95 % of children older than 30 months .
C0027361
individual
C0008059
children