Development and evaluation of a conventional RT-PCR for differentiating emerging influenza B/Victoria lineage viruses with hemagglutinin amino acid deletion from B/Yamagata lineage viruses.

Background: Recent influenza B/Victoria lineage viruses contain amino acid deletions at positions 162 to 164 of the haemagglutinin (HA) protein. These amino acid deletions have affected the detection of B/Victoria lineage viruses by the lineage-specific conventional reverse-transcription polymerase chain reaction (RT-PCR) that was recommended by World Health Organization (WHO).

Objectives: We aimed to develop and evaluate a novel lineage-specific RT-PCR for rapid differentiation of the contemporary B/Victoria lineage from B/Yamagata lineage viruses.