Comparison of Hemagglutination Inhibition Test and ELISA Assay in Detection of Measles Antibody

To compare the hemagglutination inhibition(HI)test and the ELISA assay in detection of measles antibody,the serum samples of 1317 healthy persons aged 1-24 years from Hebei Province in 1998 before and after the measles vaccine(MV)catch-up immunization were tested.The results showed that the measles antibody positive rates of HI and ELISA-IgG were 99.78% and 95.22%,the GMTs were 1∶36.15 and 1∶812.15 before MV catch-up immunization respectively.By one month after MV catch-up immunization,the measles antibody positive rates of HI and ELISA-IgG were 100% and 99.88%,the GMTs were 1∶91.65 and 1∶2158.17 respectively.Comparing the GMT of HI and ELISA-IgG before and after MV catch-up immunization,the difference was statistically significant.The two methods had closer curve correlation,the correlation coefficient was r=0.73,the 95% confidence interval was 0.70,0.75,the regression equation was Log=-0.321006+0.670756LogX 0. The paired serum samples of 58 persons who accepted MV catch-up immunization were tested by the two methods,the identical rate of ≥4 fold antibody rising was 82.76%.These results showed that HI and ELISA assay are good correlated and highly coincident.