title: Estimation of the neuraminidase content of influenza viruses and split-product vaccines by immunochromatography.
abstract: The neuraminidase (NA) of the influenza virus, as well as the hemagglutinin, is the most important protective components in the vaccine. However, the NA content of the vaccine remains to be standardized because of the labile nature of this glycoprotein during various chemical treatments and storage. In the present study, the NA content of the split-product (SP) vaccine (virus treated with ether then formalin) was estimated together with that of the virus by an immunochoromatography technique using monoclonal antibodies (mAbs) to viral NA for A/Panama/2007/99 (A/Pa) (H3N2), B/Shangdong/7/97 (B/S) or A/New Caledonia/20/99 (A/NC) (H1N1) viral strains. In the new method, the NA catalytic activity of each fraction from steps of NA purification was measured as an index of NA content. The NA level of A/Pa, B/S or A/NC viral particles was estimated at 6.9+/-0.9, 7.6+/-0.8 or 8.5+/-1.7% of total viral protein (not significant difference between viral strains). The NA level of the corresponding A/Pa, B/S or A/NC vaccines was estimated at 9.6+/-1.5, 12.7+/-0.4 or 12.2+/-1.2% of the total vaccine protein (a significant difference between each strain of virus and its vaccine). These results suggest that the NA content in the N1, N2 or B type NA virus ranges from 5 to 11% of the total viral protein, and that the NA level in each split-product vaccine is 1.4- to 1.6-fold higher than that in the corresponding viral particles. They also suggest that the NA content can be estimated by the immunochoromatography technique using anti-viral NA mAbs.
authors.affiliation: Laboratory of Prevention of Viral Disease (Research Foundation for Microbial Diseases of Osaka University), Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tanimoto
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Nakatsu
authors.forename: Isao
authors.initials: I
authors.lastname: Fuke
authors.forename: Toyokazu
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Masahide
authors.initials: M
authors.lastname: Ishibashi
authors.forename: Kouichi
authors.initials: K
authors.lastname: Yamanishi
authors.forename: Michiaki
authors.initials: M
authors.lastname: Takahashi
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Tamura
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002845:Chromatography / Q000379:methods*; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000032:analysis / Q000235:genetics; D009980:Influenza A virus / Q000201:enzymology* / Q000235:genetics / Q000276:immunology; D007252:Influenza Vaccines / Q000032:analysis*; D051379:Mice; D008807:Mice, Inbred BALB C; D009439:Neuraminidase / Q000235:genetics / Q000378:metabolism*
chemical_list: D000914:Antibodies, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines; D009439:Neuraminidase