Digest: Reassortment-based evolution of H1N1 subtype swine influenza virus in China

In a new study, Zhao et al. (2025) obtain 959 whole genome sequences of H1N1 subtype swine influenza virus (SIV) isolated from China. Their analysis of the sequences, isolated between 1977 and 2020, reveals how H1N1 lineages have co-evolved and contributed to instances of zoonotic transmission within the region. This study's findings characterize the long-term evolutionary effects of frequent viral reassortment in SIV and highlight its potential to drive future pandemics.