title: Improved colorimetric assay for detecting influenza B virus neutralizing antibody responses to vaccination and infection.
abstract: An automated neutralization test for influenza B virus is described in which antibody titers are determined according to the release of neutral red from infected or uninfected cells of the Madin-Darby canine kidney line. Endpoints are determined in a standard enzyme-linked immunosorbent assay reader. The test requires no expensive immunologic reagents and was used to evaluate responses to both vaccination and natural infection against influenza B virus. Overall responses to vaccination were comparable with those obtained by hemagglutination inhibition, using Tween-ether-split influenza B/Ann Arbor/1/86 virus as the antigen (the HI-TE test). The sensitivities of neutralization responses compared with those obtained by the HI-TE test for two vaccines were 88 and 89%; the specificities were lower at 61 and 60%, respectively. Responses to vaccination, measured by hemagglutination inhibition, were significantly higher with split virus compared with whole virus. However, seroconversion by both the HI-TE and neutralization tests was observed in 5 of 10 individuals from whom virus was detected by either culture of nasal or throat washings or the presence of antigen from immunofluorescence in cells from nasal washings.
authors.affiliation: Faculty of Medicine, University of Newcastle, New South Wales, Australia.
authors.forename: G A
authors.initials: GA
authors.lastname: Tannock
authors.forename: J A
authors.initials: JA
authors.lastname: Paul
authors.forename: R
authors.initials: R
authors.lastname: Herd
authors.forename: R D
authors.initials: RD
authors.lastname: Barry
authors.forename: A L
authors.initials: AL
authors.lastname: Reid
authors.forename: M J
authors.initials: MJ
authors.lastname: Hensley
authors.forename: R S
authors.initials: RS
authors.lastname: Gillett
authors.forename: S M
authors.initials: SM
authors.lastname: Gillett
authors.forename: P
authors.initials: P
authors.lastname: Lawrance
authors.forename: R L
authors.initials: RL
authors.lastname: Henry
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis*; D002460:Cell Line; D003124:Colorimetry; D004311:Double-Blind Method; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D009981:Influenza B virus / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology*; D007251:Influenza, Human / Q000276:immunology*; D009499:Neutral Red; D009500:Neutralization Tests; D014611:Vaccination
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines; D009499:Neutral Red