Effects Of Vaccine Hesitancy On Vaccination Behavior And Disease Transmission Based On SEM-SD Model

Background and objectives: Vaccination is the most cost-effective public health intervention to prevent and control infectious diseases,and immunization programs contribute significantly to the reduction in the prevalence and incidence of vaccine-preventable diseases(VPD).Nevertheless,delays and rejections have persisted since the vaccine was developed.In 2019,vaccine hesitancy was listed by the World Health Organization as one of the top 10 problems threatening global health.This study conducted an online questionnaire survey to explore the current status and demographic factors of vaccine hesitancy among adults in Jiangsu Province.The Structural Equation Model(SEM)based on the Protective Motivation Theory(PMT)was established to explore the influencing factors of vaccine hesitancy and vaccination behavior.A System Dynamic(SD)model of vaccine hesitancy and disease transmission was constructed to explore the dynamic changes between vaccine hesitancy,vaccination behavior and disease transmission,providing reference for vaccine hesitancy intervention and disease prevention and control.Methods:(1)An online survey was conducted on adult vaccination attitudes in Jiangsu province from May 24 to June 14,2021.The chi-square test and logistic regression analysis were used to explore the demographic factors influencing vaccine hesitancy,and the differences of vaccine hesitancy among parents,healthcare workers and the general population were compared.(2)Construct the structural equation model of extended protective motivation theory with the addition of subjective norm dimension,explain vaccine hesitancy and vaccination behavior,and explore the prediction ability of vaccine hesitancy on vaccination behavior.At the same time,the model path differences between children’s parents,healthcare workers and the general population were further investigated by SEM classification and adjustment group analysis.(3)The dynamics model of vaccine hesitancy and disease transmission was established by means of literature review and expert consultation,combined with SEM model results and infectious disease system dynamics model.The dynamic change process of population’s vaccine hesitancy and the influence trend of vaccine hesitancy on vaccination behavior and disease transmission were simulated,and the control effect of different vaccine hesitancy interventions on disease transmission was simulated.Results:(1)Among 4241 adults in Jiangsu province who were included in the study,601(14.2%)had vaccine hesitancy.A total of 1168 parents of children aged 0 to 6 years were included,and 12% of them had vaccine hesitancy.13.7% of the 1,173 healthcare workers who participated in the survey reported vaccine hesitancy.The absence of chronic diseases,good self-assessment of health status and previous vaccination experience had a significant negative impact on vaccine hesitancy among adults and parents.(2)The extended PMT model explained50.4% variance of vaccine hesitancy and 11.5% variance of vaccination behavior.Perceived severity,response efficacy,self-efficacy and subjective norms had negative effects on vaccine hesitancy,while response cost had positive effects on vaccine hesitancy.Subjective norm was the strongest predictor in the model(β=-0.516;P<0.001).Vaccine hesitancy had a negative effect on vaccination behavior(β=-0.339;P<0.001).The effect of response cost on vaccine hesitancy was not statistically significant in the children’s parents group,while self-efficacy was not statistically significant in the non-children’s parents group.(3)The results of system dynamics showed that after vaccination,the number of susceptible people decreased and reached a stable state earlier,while the peak value of infected people decreased and peaked earlier.Vaccine hesitancy levels showed a downward trend during the spread of the disease,then slowly returned to their original levels.In addition,different intervention dimensions have different response levels,among which the effect of subjective norm dimension is significantly better than other dimensions,followed by response efficacy,perceived severity,response cost and self-efficacy dimensions.Conclusions: There is a certain level of vaccine hesitancy among adults in Jiangsu Province,and demographic characteristics can provide reference for targeted vaccine hesitancy intervention.The extended PMT model can effectively predict vaccine hesitancy and vaccination behavior,and vaccine hesitancy has a significant negative effect on vaccination behavior.When the intervention of vaccine hesitancy,attention can be paid to improve the effect of intervention from the perspective of subjective norms,so as to increase vaccine coverage and control the spread of disease.