Abstract: ObjectiveTo determine the efficacy of measles vaccines and measles antibody levels in healthy people in Tiantai county, Zhejiang province, and identify the causes of increase in measles outbreaks. MethodsA total of 65 randomly chosen healthy children were informed to receive basic immunization, whose peripheral blood were collected for measles antibody detection before and after immunization, respectively. Additional 360 random healthy subjects derived from each age group were recruited, providing peripheral blood samples for measles antibody detection. ResultsThe antibody-positive rate in terms of measles antibodies amongst children was 12.31% before immunization, but reached 83.08% within one month after basic immunization in Tiantai in 2008. The immunization success rate was 80.70%. Eight-month-old and older healthy infants had a positive rate of 85.87% without significant difference in the positive rates between age groups (I/Isup2/sup=9.98, IP/I＞0.05). ConclusionRelatively low success rate of basic immunization against measles, as well as low positive rate of measles antibodies amongst healthy people, was revealed in Tiantai. Therefore, inspection and supervision of programmed immunization shall be performed, appropriate groups included into the scope, and catch-up immunization carried out in a timely manner.