title: Increased sensitivity and reduced specificity of hemagglutination inhibition tests with ether-treated influenza B/Singapore/222/79.
abstract: Hemagglutination inhibition (HI) tests against whole virus (WV) influenza B/Singapore/222/79 antigen detected prevaccination serum antibody in only 15 (20%) of 50 predominantly elderly volunteers and fourfold or greater titer rises in only three (6%) after they received 1981-1982 trivalent influenza vaccine containing antigens of this virus. HI titers against ether-treated (ET) B/Singapore/222/79 were about eightfold higher than those against WV antigen and were comparable to microneutralization titers against this virus. The ET HI detected prevaccination antibody in 84%, a postvaccination titer rise in 32%, and a final titer of 80 or higher in 66%. Among 51 additional persons with known or presumed influenza B virus infections early in 1982, ET B/Singapore/222/79 was also more sensitive than WV for serodiagnosis (69 versus 49%), but eight persons with both WV and ET B/Singapore/222/79 HI responses also had an HI titer rise to WV A/Brazil/11/78 (H1N1) antigen. Conversely, among 14 college students with febrile, culture-proven influenza A (H1N1) infections early in 1982, 6 (43%) developed HI titer rises to ET B/Singapore/222/79 with no other serological evidence of influenza B virus infection. Moreover, young adult volunteers with mild experimental influenza A (H1N1) infections also exhibited a 17% (3 of 18) incidence of ET B/Singapore/222/79 HI titer rises, versus none in matched, uninfected volunteers. These data indicate that ET B/Singapore/222/79 virus has increased sensitivity but reduced specificity compared to WV as an HI antigen and that caution is needed in interpretation of a single HI test for serodiagnosis, whether with WV or ET antigen.
mesh_terms: D000368:Aged; D000914:Antibodies, Viral / Q000032:analysis; D000918:Antibody Specificity; D055598:Chemical Phenomena; D002621:Chemistry; D004986:Ether; D006385:Hemagglutination Inhibition Tests / Q000379:methods; D006801:Humans; D007252:Influenza Vaccines / Q000276:immunology; D007251:Influenza, Human / Q000175:diagnosis / Q000382:microbiology*; D009975:Orthomyxoviridae / Q000276:immunology*; D012698:Serologic Tests
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines; D004986:Ether