Virus susceptibility analyses from a phase IV clinical trial of inhaled zanamivir treatment in children infected with influenza.

ABSTRACT: A zanamivir postapproval efficacy study was conducted in children (n = 279) in Japan during three influenza seasons. Pharyngeal swab specimens (n = 714) were obtained for detailed resistance analysis. From 371 cultured viruses, 3 viruses (A/H1N1) from two subjects showed reduced susceptibility to zanamivir at day 1 (before treatment), 1 had an N74S amino acid substitution (fold shift, 46), and 2 (day 1 and day 2) had a Q136K amino acid substitution (fold shifts, 292 and 301). Q136K was detected only in cultured virus and not in the swab. From the remaining 118 cultured viruses obtained during or after treatment with zanamivir, no shifts in virus susceptibility were detected. Neuraminidase (NA) population sequencing showed that viruses from 12 subjects had emergent amino acid substitutions,

SUBMITTER: Yates PJ 

PROVIDER: S-EPMC3623313 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature