Long-term epidemiology and evolution of swine influenza viruses in Vietnam

Swine influenza virus (SwIV) surveillance in Hanoi, Vietnam from 2013—2019 found gene pool enrichment from imported swine from Asia and North America. Long-term maintenance, persistence and reassortment of SwIV lineages was observed. Co-circulation of H1-δa viruses with other SwIV genotypes raises concern due to its zoonotic potential. ### Competing Interest Statement The authors have declared no competing interest.