The declining antibody level of measles virus in China population, 2009–2015

Background To eliminate measles, the coverage of more than 90% vaccine is required in China. Nonetheless, the measles incidence still reached to 3.88 per 100,000 in 2014, which is far more than the target of 1 per 1,000,000. Moreover, there is little national surveillance to measles antibody level indicating herd immunity status in China. Methods We detected the level of antibody to measles using commercially available indirect enzyme-linked immunosorbent IgG assays, and calculated the protection rate of population (PRP) to measles virus infection among health peoples in China. Results During the years 2009–2015, among the Chinese population aged 0–56, PRP was 94.7, 91.6, 91.6, 84.2, 82.1, 81.0, 75.4%, respectively. Among all age bands, the PRP is lowest among children less than 12-month-age, followed by people over 15 years old. Conclusion Measles antibody level among healthy population has been declined since 2012, supplemented measles vaccination activity may be necessary to eliminate measles in China.