RESUMEN
Objective:To determine the level of anti-measles antibody in healthy population aged 1-14 years old in Shanghai， and project the risk of measles incidence in adult population in the future， which may provide evidence for enhancing the measles immunization strategy. Methods:A cross-sectional study was conducted to collect the serum of healthy people aged 1-14 years old in an urban district hospital in Shanghai. Serum concentration of anti-measles IgG antibody was examined by enzyme-linked immunosorbent assay （ELISA） and dynamics of IgG antibody was compared. Results:The prevalence of anti-measles antibody in healthy people aged 1-14 years old was determined to be 95.29%， and the antibody protection rate was 61.86%. There was no significant difference in the distribution of antibody between men and women （P>0.05）. However， there was statistical difference in the distribution of antibody among different age groups （P<0.05）， in which the antibody showed a decreasing trend with age， especially after the age of 10 years. The lowest prevalence of anti-measles antibody and protection rate were observed in the population aged 13-14 years old， which were 87.41% and 22.96%， respectively. The GMT was 2.667 1 （equal to the concentration of anti-measles IgG antibody being 464.62 mIU/mL）. According to the fitting model Ŷ =3.217-0.04X（R2=0.943，P<0.05）， the antibody protection rate was projected to decrease to zero in the population aged 19-20 years old， whereas the anti-measles antibody was to zero in the population aged 29-30 years old . Conclusion:As there is almost no natural infection of measles，the anti-measles antibody after measles vaccine immunization showed a linearly decreasing trend with age after measles immunization．It is recommended that people aged 10-15 years should be administered intensive immunization for prevention of adults measles，which could be incorporated into current measles immunization strategies.
RESUMEN
Objective] To analyze the effect of enhanced immunization for school-age children in Hongkou District of Shanghai in immunology and epidemiology . [ Methods] One month after completing immunization, the blood antibody titers were measured by ELISA method , and compared with the those of non-enhanced immunization , for epidemiological survey were collected history of measles immunization and close contact with the measles . [ Results] It could not be thought that strengthening immunization im-proved antibody positivity rate , the protection rate , and geometric antibody average concentrations .There was not statistical difference in antibody levels between measles vaccination 2 times and 3 -4 times. [ Conclusion] In the regions where routine immunization rates reach a high level , strengthening immuni-zation done on large scale is a waste of vaccine resources , human resources and financial resources , and leak re-vaccination should be done as a cost-effective preventive measure .