Fig. 2
From: The declining antibody level of measles virus in China population, 2009–2015
the age specific protection rate of measles virus among health population in China, 2009 to 2015. a: the protection rate of measles virus among children less than 12 months; b, the protection rate of measles virus among children between one-year-old and four-year-old; c, the protection rate of measles virus among children between five-year-old and 14year-old; d, the protection rate of measles virus among population more than 14 years old