title: Evaluation of the infectivity, immunogenicity, and efficacy of live cold-adapted influenza B/Ann Arbor/1/86 reassortant virus vaccine in adult volunteers.
abstract: A cold-adapted (ca) influenza B reassortant that derived two genes encoding the hemagglutinin and neuraminidase from influenza B/Ann Arbor/1/86 wild-type virus and six internal RNA segments from ca influenza B/Ann Arbor/1/66 virus was evaluated in 66 adult volunteers having a serum hemagglutination inhibition antibody titer less than or equal to 1:8. The ca reassortant was attenuated and elicited the production of systemic and local antibodies; the 50% human infectious dose was 10(6.4) TCID50. Six weeks after vaccination, 12 unvaccinated volunteers and 13 recipients of ca virus (10(7.5) TCID50) were challenged experimentally with homologous wild-type influenza B virus. The ca vaccine completely protected against illness, and the magnitude of shedding was 50-fold less in vaccinees than in unimmunized controls, five of whom became ill. These findings indicate that the six internal RNA segments of the ca influenza B/Ann Arbor/66 donor virus confer desirable properties of a live virus vaccine to a reassortant derived from a virulent virus. Such reassortants may be suitable vaccines for healthy adults.
authors.affiliation: Center for Immunization Research, Johns Hopkins University School of Hygiene and Public Health, Baltimore, Maryland 21205.
authors.forename: M L
authors.initials: ML
authors.lastname: Clements
authors.forename: M H
authors.initials: MH
authors.lastname: Snyder
authors.forename: S D
authors.initials: SD
authors.lastname: Sears
authors.forename: H F
authors.initials: HF
authors.lastname: Maassab
authors.forename: B R
authors.initials: BR
authors.lastname: Murphy
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000096:biosynthesis*; D004306:Dose-Response Relationship, Immunologic; D004797:Enzyme-Linked Immunosorbent Assay; D006385:Hemagglutination Inhibition Tests; D006389:Hemagglutinins, Viral / Q000235:genetics; D006801:Humans; D009981:Influenza B virus / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D007252:Influenza Vaccines / Q000009:adverse effects / Q000276:immunology*; D007251:Influenza, Human / Q000517:prevention & control*; D009439:Neuraminidase / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D014613:Vaccines, Attenuated / Q000009:adverse effects / Q000276:immunology; D014614:Vaccines, Synthetic / Q000009:adverse effects / Q000276:immunology; D014779:Virus Replication
chemical_list: D000914:Antibodies, Viral; D006389:Hemagglutinins, Viral; D007252:Influenza Vaccines; D012367:RNA, Viral; D014613:Vaccines, Attenuated; D014614:Vaccines, Synthetic; D009439:Neuraminidase