Modelling the effect of vaccination on the transmission dynamics of measles in China

Measles is a highly contagious acute respiratory disease. In recent years, substantial progress has been made in the prevention and control of measles in China. However, the complete eradication of measles remains a challenge, as the incidence rate continues to be elevated in some regions. Understanding the transmission dynamics of measles is thus crucial. In this study, we developed a mathematical model to mimic the effect of vaccination in controlling the measles. The model was parameterized using actual measles data from October 2016 to September 2019, covering the nationwide China, as well as Guangdong, Yunnan and Hebei provinces. We estimated the value of basic reproduction number ( $R_{0}$ ) for measles transmission over this three-year period and calculated the partial rank correlation coefficients (PRCCs) of $R_{0}$ with respect to the parameters. Contour plots were drawn and other sensitivity analysis was carried out to investigate the effect of variation of key parameters on the measles transmission. We found that $R_{0}$ is most sensitive to the transmission rates, vaccination rate and immunization success rate. The peak time is advanced and the peak size decreases if the vaccination rate increased and the success rate of immunization increased or the failure rate of immunization decreased. The main results show that raising public awareness, timely isolation of infecteds and conducting vaccination statistics surveys can significantly reduce the risk of measles outbreak. Reducing measles infection rates, strengthening vaccination and enhancing the vaccine-induced immunity can effectively control the spread of measles in China.