title: Evaluation of a cold-adapted influenza B/Texas/84 reassortant virus (CRB-87) vaccine in young children.
abstract: A cold-adapted (ca) influenza B reassortant virus vaccine that contained the six internal RNA segments from influenza B/Ann Arbor/1/66 ca virus and the neuraminidase and hemagglutinin genes from wild-type influenza B/Texas/1/84 virus was evaluated in children ranging in age from 8 months to 14 years. The children were vaccinated intranasally with doses ranging from 10(3.2) to 10(6.2) 50% tissue culture infective doses (TCID50). Thirty children were seropositive, and 26 were seronegative. Thirty-three children participated as unvaccinated controls. The vaccine was well tolerated by both seronegative and seropositive children. The amount of virus required to infect 50% of seronegative children was approximately 10(4.5) TCID50. Vaccine viruses recovered from airway secretions retained temperature-sensitive and cold-adapted characteristics. The results of this study indicate that the vaccine virus, influenza B/Texas/84 ca reassortant virus, is attenuated, immunogenic, and phenotypically stable when given to young seronegative children.
authors.affiliation: Department of Internal Medicine, St. Louis University School of Medicine, Missouri 63104.
authors.forename: E L
authors.initials: EL
authors.lastname: Anderson
authors.forename: F K
authors.initials: FK
authors.lastname: Newman
authors.forename: H F
authors.initials: HF
authors.lastname: Maassab
authors.forename: R B
authors.initials: RB
authors.lastname: Belshe
mesh_terms: D000220:Adaptation, Biological; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003080:Cold Temperature; D005069:Evaluation Studies as Topic; D014644:Genetic Variation; D006801:Humans; D007223:Infant; D009981:Influenza B virus / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology*; D007251:Influenza, Human / Q000517:prevention & control*; D010641:Phenotype; D014613:Vaccines, Attenuated / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000276:immunology*
chemical_list: D007252:Influenza Vaccines; D014613:Vaccines, Attenuated; D014614:Vaccines, Synthetic