title: Evaluation of immunogenicity of the 2008-2009 seasonal influenza vaccines by microneutralization test.
abstract: OBJECTIVE
  For evaluating the immunogenicity of an influenza vaccine, the microneutralization (MN) test has a higher sensitivity and specificity as compared to the hemagglutination inhibition (HI) test. However, the MN test is more time consuming and is difficult to standardize. We performed the MN test to determine its usefulness as an alternative or complementary test to the HI test for evaluating the immunogenicity of influenza vaccines.
  
  
  METHODS
  We compared the MN test with the HI test using 50 paired samples taken from a previous clinical study (2008-2009) in Korean children under 18 years of age.
  
  
  RESULTS
  The linear correlation coefficients of the 2 tests for H3N2, H1N1, and influenza B were 0.69, 0.70, and 0.66, respectively. We identified a high index of coincidence between the 2 tests. For an influenza vaccine, the postvaccination seroprotection rates and seroconversion rates determined by the MN test were 78.0% and 96.0%, 90% and 42.0%, and 42.0% and 48.0% for H3N2, H1N1, and influenza B, respectively. Geometric mean titer fold increases of H3N2, H1N1, and influenza B were 2.89, 5.04, and 4.29, respectively, and were 2.5-fold higher. We obtained good results in the evaluation of the immunogenicity of the 2008-2009 seasonal influenza vaccines.
  
  
  CONCLUSIONS
  We found that the MN test was as effective as the HI test. Therefore, we suggest that the MN test can be used as an alternative or complementary test to the HI test for evaluating the immunogenicity of influenza vaccines.
authors.affiliation: Department of Pediatrics, Korean Cancer Center Hospital, Seoul, Korea.
authors.forename: Seung Youn
authors.initials: SY
authors.lastname: Kim
authors.forename: Yun Kyung
authors.initials: YK
authors.lastname: Kim
authors.forename: Byung Wook
authors.initials: BW
authors.lastname: Eun
authors.forename: Nam Hee
authors.initials: NH
authors.lastname: Kim
authors.forename: Eun Kyeong
authors.initials: EK
authors.lastname: Kang
authors.forename: Byong Sop
authors.initials: BS
authors.lastname: Lee
authors.forename: Jung Sub
authors.initials: JS
authors.lastname: Lim
authors.forename: Jun Ah
authors.initials: JA
authors.lastname: Lee
authors.forename: Dong Ho
authors.initials: DH
authors.lastname: Kim
keywords: Child; Hemagglutination inhibition test; Influenza vaccines; Neutralization tests