Measles, a highly contagious infection caused by the measles virus, is a
major public-health problem in China. The reported measles cases decreased
dramatically from 2004 to 2012 due to the mandatory measles vaccine
program started in 2005 and the goal of eliminating measles by 2012.
However, after reaching its lowest level in 2012, measles has resurged
again since 2013. Since the monthly data of measles cases exhibit a
seasonally fluctuating pattern, based on the measles model in Earn et
al.(Science 287(2000), 667-670) we propose a susceptible, exposed,
infectious, and recovered (SEIR) model with periodic transmission rate to
investigate the seasonal measles epidemics and the effect of vaccination.
We calculate the basic reproduction number R_0, analyze the dynamical
behavior of the model, and use the model to simulate the monthly data of
measles cases reported in China. We also carry out some sensitivity
analysis of R_0 in the terms of various model parameters which shows that
measles can be controlled and eventually eradicated by increasing the
immunization rate, improving the effective vaccine management, and
enhancing the awareness of people about measles.