ABSTRACT
Objective To evaluate the protective rate and the variation of HFRS-IgG on hemorrhagical fever with renal syndrome (HFRS) vaccine.Methods Cluster,random sampling and cross-sectional study were used to assess the protective rate of HFRS vaccination.Level of HFRS-IgG was detected with ELISA in epidemic and non-epidemic areas of HFRS.Results Curve equation was obtained as Yprocective rate=(0.863+0.283/Xvaccination term) × 100％ by protective rate with vaccination term.Protective rates showed a reducing trend,90％ after 7-8 years of vaccination,88％ after 10 years,and 94％ on average.Absorbance (A) value of HFRS-IgG was 4 times higher in persons with vaccination than those without,in the epidemic area.Higher antibody level could be obtained after primary vaccination,but the level of antibody had a 50％ reduction after 5-10 years of vaccination,and a 60％ reduction after 10 years of vaccination.Conclusion HFRS antibody had a 50％ reduction after 5-10 years of vaccination.The protective rate of HFRS vaccination had a 90％ loss,after 7-8 years of vaccination.Booster dose was necessary after 7 years of vaccination.