Abstract:

Objective To investigate measles antibody levels in females aged 20-40 in Dali Bai Autonomous Prefecture，and to formulate a measles vaccination strategy and provide scientific evidence for children under 8 months. Methods Totally，4 908 females in Dali Bai Autonomous Prefecture were enrolled from 2016 to 2020，and measles IgG antibody was determined. The geometric mean concentration（GMC） of measles antibodies was calculated. Administrative region，ethnicity，age，region（urban，rural），measles containing vaccine（MCV） immunization history and measles history were collected. When the concentration of measles IgG antibody was ≥250 mIU，it was considered positive. When measles IgG antibody reached ≥800 mIU，it was considered to provide protection against measles. Multivariate Logistic regression model was used to analyze the influence factors for measles antibody positivity. Results Through an epidemiological survey of 4 908 females from 20 to 40 years old，the measles antibody positive rate was 91.4%，the protection rate was 63.1%，and the measles antibody GMC was 1 010.25 mIU/mL. There was statistical significance in the positive rate of measles antibody，measles antibody protection rate and measles antibody GMC between different years and administrative districts（P<0.05）. There was statistical significance in the positive rate of measles antibody，measles antibody protection rate and measles antibody GMC among different ethnic groups and MCV immunization history（P<0.05）. There was no statistical significance in the positive rate and protection rate of measles antibody among different age groups and regions（P>0.05）. The difference in measles antibody GMC for females was statistically significant among different age groups（P<0.05）. There was no statistical significance in measles antibody GMC between urban and rural（P>0.05）. There was no statistical significance for the positive rate of measles antibody，the protection rate of measles antibody and the GMC of measles antibody whether there was measles history（P>0.05）. Multivariate Logistic regression analysis showed that ethnicity and MCV immunization history were influence factors. The odds ratios（OR） were 0.896 and 1.776，and 95% confidence intervals（CI） were 0.842-0.952 and 1.425-2.214，respectively. Conclusions Increasing the vaccination rate of Dali Bai Autonomous Prefecture's females to MCV can effectively reduce the risk of measles infection in children under 8 months.

Key words: Measles virus, Immunoglobulin G antibody, Female, Dali Bai Autonomous Prefecture