RT Journal Article SR Electronic T1 Differential Disease Severity and Whole Genome Sequence Analysis for Human Influenza A/H1N1pdm Virus in 2015-2016 Influenza Season JF bioRxiv FD Cold Spring Harbor Laboratory SP 2020.02.20.957068 DO 10.1101/2020.02.20.957068 A1 Hsuan Liu A1 Yu-Nong Gong A1 Kathryn Shaw-Saliba A1 Thomas Mehoke A1 Jared Evans A1 Zhen-Ying Liu A1 Mitra Lewis A1 Lauren Sauer A1 Peter Thielen A1 Richard Rothman A1 Kuan-Fu Chen A1 Andrew Pekosz YR 2020 UL http://biorxiv.org/content/early/2020/10/03/2020.02.20.957068.abstract AB During the 2015-16 winter, the US experienced a relatively mild influenza season compared to Taiwan which had a higher number of total and severe cases. While H1N1pdm viruses dominated global surveillance efforts that season, the global distribution of genetic variants and their contributions to disease severity have not been investigated. Samples collected from influenza A positive patients by the Johns Hopkins Center of Excellence for Influenza Research and Surveillance (JH-CEIRS) active surveillance in the emergency rooms in Baltimore, Maryland, USA and northern Taiwan between November 2015 and April 2016, were processed for influenza A virus whole genome sequencing. In Baltimore, the majority of the viruses were the H1N1pdm clade 6B.1 and no H1N1pdm clade 6B.2 viruses were detected. In northern Taiwan, more than half of the H1N1pdm viruses were clade 6B.1 and 38% were clade 6B.2, consistent with the global observation that most 6B.2 viruses circulated in Asia and not North America. Whole virus genome sequence analysis identified two genetic subgroups present in each of the 6B.1 and 6B.2 clades and one 6B.1 intraclade reassortant virus. Clinical data showed 6B.2 patients had more disease symptoms including higher crude and inverse probability weighted odds of pneumonia than 6B.1 patients, suggesting 6B.2 circulation may contribute to the severe flu season in Taiwan. Local surveillance efforts linking H1N1pdm virus sequences to patient clinical and demographic data improve our understanding of influenza circulation and disease potential.Competing Interest StatementThe authors have declared no competing interest.