Monitoring and Evaluation of Measles Vaccine Efficacy and Study on strategy of Measles Control in Yunnan Province

Objective To analyse the reason of high measles incidence in Yunnan,and formulate strategy of Measles Control. Methods To study the impact of cold chain running to the efficiency of Measles Vaccine and evaluate vaccine effect to the Measles vaccine by field epidemiological investigation and Lab test. Results The average efficiency of measles vaccine from five levels monitoring, fixed site monitoring, and two levels monitoring are 3.0 1g CCID50/ml. 21 strain of measles virus isolated from the sample collected from different outbreak places are H1 by genotype identification. 85 and 74 chiblren with of measles antibody negative were administrated 0.2ml and 0.5ml measles vaccine respectively before immuniration. The measles vaccine immunization success rates were 88.24% and 97.30% (P0.05).The study collected 3815 blood samples,population aged from 1-20years old.Among them,3663 was measles IgG positive (96.02%).The measles antibody geometric mean titer (GMT) was 1∶843.The measles antibody protection rate (1∶800) was 71.85%.The coverage rates of measles vaccine (MV) based on immunization was 75.05%,and the second dose of MV 46.53%. Conclusion The existed cold chain system can ensure the measles vaccine efficacy during normal transportation in yunnan province.Separates H1 type measles virus in Yunnan is consistent with China as primary measles pathogen.The reason of high measles incidence in Yunnan was due to effective coverage rate of measles vaccine lower than 95% targets which blocks measles transmission in Yunnan Province.To raise the measles vaccine effective vaccination coverage and develop the measles vaccine with supplementary immunization activities (SIAs) are the main strategy of measles control at present in Yunnan Province.