Enhanced replication of a contemporary avian influenza A H9N2 virus in human respiratory organoids.

ABSTRACT: H9N2 is currently the second most common avian influenza A virus subtype infecting humans. Monitoring viral phenotypic and genotypic adaptation to humans is crucial for risk assessment. Here, we compared the replication of an H9N2 human isolate collected in 2024 (A/HK/2346/2024) to a human isolate collected in 1999 (A/HK/1073/1999). In Madin Darby canine kidney (MDCK) cells, A/HK/2346/2024 and A/HK/1073/1999 replicated to 8 and 5 log10 plaque-forming units (PFU) per ml, respectively. In both human nasal and lung organoids, A/HK/2346/2024 replicated to 6 log10 PFU/ml, but A/HK/1073/1999 failed to replicate in either organoid. The infection rates of both ciliated and non-ciliated cells and the ratios of infected 2,6/2,3 cells were higher for A/HK/2346/2024 than A/HK/1073/1999. Apart from the

SUBMITTER: Chen LL 

PROVIDER: S-EPMC12584838 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature