title: [The changes in serum antibody level after immunization with HFRS vaccine].
abstract: OBJECTIVE
  To observe the changes in serum antibody level after mass immunization with vaccine against hemorrhagic fever with renal syndrome (HFRS) and to evaluate its efficacy and effectiveness in the prevalent areas.
  
  
  METHODS
  Healthy people aged 16 to 60 years in the villages were recruited as study subjects, excluding those suffered from HFRS previously, going out for more than nine months and those with contraindications, and were randomly allocated into immunization and control groups with 10,460 and 16,159 persons, respectively. Specific IgG antibody was determined with indirect immunofluorescent assay (IFA) and neutralizing antibody (NA) was determined with micro CPE method.
  
  
  RESULTS
  Two weeks after the full-course immunization, sero-conversion rate for IFA reached 100% in those sero-negative before immunization, with a 95% confidence interval of 96.3 - 100.0%, and that for NA 44.4%, with a 95% CI of 22.0% - 69.0%. Geometric mean titer (GMT) were 72.1 and 4.6 for IFA and NA, respectively. Booster immunization was provided for them one year later. Positivity of IFA and NA was 28.6%, 83.3%, 75.0%, 53.1%, 22.6% and 14.8%, 55.6%, 35.0%, 31.3%, 26.0%, before booster immunization, two weeks, one year, one and a half years, two years after booster immunization, respectively.
  
  
  CONCLUSIONS
  HFRS vaccine had good immunogenicity, but its duration of serum antibody sustenance was relatively short.
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310009, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Gong
authors.forename: J
authors.initials: J
authors.lastname: Weng
authors.forename: Z
authors.initials: Z
authors.lastname: Zhao
authors.forename: J
authors.initials: J
authors.lastname: Lan
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.forename: C
authors.initials: C
authors.lastname: Lin
authors.forename: G
authors.initials: G
authors.lastname: Fu
authors.forename: Z
authors.initials: Z
authors.lastname: Zhu
authors.forename: J
authors.initials: J
authors.lastname: Xia
authors.forename: Q
authors.initials: Q
authors.lastname: Ji
authors.forename: J
authors.initials: J
authors.lastname: Xu
authors.forename: C
authors.initials: C
authors.lastname: Wang
authors.forename: X
authors.initials: X
authors.lastname: Yu
authors.forename: W
authors.initials: W
authors.lastname: Wang
authors.forename: C
authors.initials: C
authors.lastname: Fang
mesh_terms: D000293:Adolescent; D000328:Adult; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood*; D005260:Female; D006480:Hemorrhagic Fever with Renal Syndrome / Q000517:prevention & control*; D006801:Humans; D007114:Immunization; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D015164:Vaccines, Inactivated / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*; D055815:Young Adult
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D007074:Immunoglobulin G; D015164:Vaccines, Inactivated; D014765:Viral Vaccines