title: Qualitative and quantitative analyses of virtually all subtypes of influenza A and B viral neuraminidases using antibodies targeting the universally conserved sequences.
abstract: Neuraminidase-induced immune responses are correlated with protection of humans and animals from influenza. However, the amounts of neuraminidase in influenza vaccines are yet to be standardized. Thus, a simple method capable of quantifying neuraminidase would be desirable. Here we identified two universally conserved sequences in all influenza A and B neuraminidases, one representing a novel finding of nearly 100% conservation near the enzymatically active site. Antibodies generated against the two highly conserved sequences bound to all nine subtypes of influenza A neuraminidase and demonstrated remarkable specificity against the viral neuraminidase sequences without any cross-reactivity with allantoic and cellular proteins. Importantly, employing these antibodies for the analyses of vaccines from eight manufacturers using the same vaccine seeds revealed marked variations of neuraminidase levels in addition to considerable differences between lots from the same producer. The reasons for the absence or low level of neuraminidase in vaccine preparations are complex and could be multi-factorial. The antibody-based assays reported here could be of practical value for better vaccine quality control.
authors.affiliation: Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, HPFB, Health Canada, Ottawa, ON, Canada.
authors.forename: Caroline
authors.initials: C
authors.lastname: Gravel
authors.forename: Changgui
authors.initials: C
authors.lastname: Li
authors.forename: Junzhi
authors.initials: J
authors.lastname: Wang
authors.forename: Anwar M
authors.initials: AM
authors.lastname: Hashem
authors.forename: Bozena
authors.initials: B
authors.lastname: Jaentschke
authors.forename: Kang-wei
authors.initials: KW
authors.lastname: Xu
authors.forename: Barry
authors.initials: B
authors.lastname: Lorbetskie
authors.forename: Genevieve
authors.initials: G
authors.lastname: Gingras
authors.forename: Yves
authors.initials: Y
authors.lastname: Aubin
authors.forename: Garry
authors.initials: G
authors.lastname: Van Domselaar
authors.forename: Michel
authors.initials: M
authors.lastname: Girard
authors.forename: Runtao
authors.initials: R
authors.lastname: He
authors.forename: Xuguang
authors.initials: X
authors.lastname: Li
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000914:Antibodies, Viral / Q000276:immunology*; D000918:Antibody Specificity; D017124:Conserved Sequence; D003429:Cross Reactions; D009980:Influenza A virus / Q000201:enzymology*; D009981:Influenza B virus / Q000201:enzymology*; D007252:Influenza Vaccines / Q000276:immunology; D009439:Neuraminidase / Q000032:analysis* / Q000276:immunology; D017386:Sequence Homology, Amino Acid
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D007252:Influenza Vaccines; D009439:Neuraminidase