title: Detection and characterization of new influenza B virus variants in 2002.
abstract: One-hundred five influenza B-positive specimens obtained from southeast Asia in 2002 were categorized on the basis of DNA sequencing of HA1 gene as well as real-time PCR analysis of the NA gene. Phylogenetic analysis of the HA1 gene sequences showed that the majority of the viruses (96.2%) belonged to the B/Victoria/2/87 lineage, while a smaller percentage of the viruses (3.8%) belonged to the B/Yamagata/16/88 lineage. The B/Yamagata/16/88 viruses displayed significant antigenic drift in the deduced amino acid sequences of the HA1 protein, and the B/Victoria/2/87-like viruses consisted of B/Hong Kong/1351/02-like (72.3%) and B/Hong Kong/330/01-like (27.7%) viruses. The B/Hong Kong/1351/02-like viruses were reassortants with the HA gene belonging to the B/Victoria/2/87 lineage and the NA gene belonging to the B/Yamagata/16/88 lineage, whereas both the HA and NA genes of B/Hong Kong/330/01 virus belonged to the B/Victoria/2/87 lineage. In this study, however, all the B/Hong Kong/330/01-like isolates exhibited the B/Yamagata/16/88-like NA gene, which likely resulted from reassortment of B/Hong Kong/330/01 and B/Hong Kong/1351/02 viruses during coinfection. Additional molecular characterization of the six internal genes showed that the M, NS, PA, and PB2 genes of the new variants were B/Hong Kong/1351/02 in origin, whereas the NP and PA genes retained the B/Hong Kong/330/01 origin. Interestingly, these new variants all appeared late in the year 2002. These results support the notion that influenza B viruses continued to evolve through antigenic drift and shift.
authors.affiliation: Clinical Immunology and Virology Department, Applied Immunology and Microbiology Division, Wyeth Vaccines Research, Bldg. 180, 401 N. Middletown Rd., Pearl River, NY 10965, USA.
authors.forename: X Sherry
authors.initials: XS
authors.lastname: Chi
authors.forename: Aizhong
authors.initials: A
authors.lastname: Hu
authors.forename: Trentice V
authors.initials: TV
authors.lastname: Bolar
authors.forename: Wafa
authors.initials: W
authors.lastname: Al-Rimawi
authors.forename: Ping
authors.initials: P
authors.lastname: Zhao
authors.forename: John S
authors.initials: JS
authors.lastname: Tam
authors.forename: Ruth
authors.initials: R
authors.lastname: Rappaport
authors.forename: Sheau-Mei
authors.initials: SM
authors.lastname: Cheng
mesh_terms: D001483:Base Sequence; D002675:Child, Preschool; D017931:DNA Primers; D014644:Genetic Variation; D006801:Humans; D007223:Infant; D009981:Influenza B virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D007251:Influenza, Human / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology*; D008969:Molecular Sequence Data; D009518:New York / Q000453:epidemiology; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D017931:DNA Primers