Support from the @ceirrnetwork.bsky.social and @johnshopkinsmmi.bsky.social helped drive this work. 6/6

All of which may speak to the importance of balancing antigenic changes with replication fitness changes in order for IBVs to maintain their ability to circulate in humans. There is a lot that IBV can teach us about respiratory virus circulation. 5/6

The emergence of the C.5 clade of IBV came with a slight loss of replication fitness but its replacement by clade C.5.1 seemed to be driven more by increased replication fitness and not by antigenic changes. 4/6

...and with respect to their in vitro replication fitness (measured by plaque size and replication in human nasal epithelial cell cultures) at both 33C and 37C. 3/6

We looked at influenza B viruses from 2020 to 2024 to see how they changed antigenically (recognition by serum from influenza vaccinated individuals)... 2/6

lovely signature for influenza C virus. rarely surveilled for in the US but it holds a special place in my mind as i spent 4 years as a postdoc working on it.