2019-20 H1N1 clade A5a.1 viruses have better in vitro replication compared with the co-circulating A5a.2 clade.
Swanson, Nicholas J, Paula Marinho, Amanda Dziedzic, Anne Jedlicka, Hsuan Liu, Katherine Fenstermacher, Richard Rothman, and Andrew Pekosz. 2023. “2019-20 H1N1 Clade A5a.1 Viruses Have Better in Vitro Replication Compared With the Co-Circulating A5a.2 Clade.”. BioRxiv : The Preprint Server for Biology.