Study on factors related to immunization effect of measles cases

ObjectiveTo analyze the immunization status of measles cases, explore the factors related to the immunization effect and the measles control measures. MethodsAccording to the laboratory results of surveillance cases, the laboratory confirmed measles cases were selected in Henan province in 2007, and the cases were divided into subgroups according to the immunization status. The factors related to the immunization effect were analyzed on the phenomenon that some cases occurred before the first dose of immunization or after immunization and measles control measures were suggested. ResultsA total of 3912 confirmed measles cases were selected, among which 1079 had vaccination history, 679 aged less than 8 months (the time to start the first dose of immunization), 1325 were age suitable but not immunized and 829 had unknown immunization history. Among 699 measles cases with known date of immunization, 336 occurred within one year after immunization, 111 occurred during 1-2 years after immunization, 60 occurred during 2-3 years after immunization, 59 occurred during 3-4 years after immunization and 133 occurred 4 years later after immunization. ConclusionWith the implementation of measles vaccination, two type cases were observed, I.e. the case occurred after immunization and the case occurred before the first dose of immunization. The reasons for which might include the change on immunogenicity of the vaccine and the level of maternal antibody. So the control measures were suggested, I.e. improving routine measles immunization coverage and successful rate to interrupt the circulation of wild measles virus, and vaccination of the women of childbearing age to improve the protection of maternal antibody.