Gagandeep Singh, D. Bhavsar, Lucas M. Ferreri, Jessica R Nardulli, C. Gleason, N. Lyttle, Yuexing Chen, A. Lowen, V. Simon, Florian Krammer
2026.5.1Eurosurveillance
tlooto Summary
Characterised antibody responses to avian influenza A(H9N2) viruses in 298 human sera from adults in New York City and observed widespread cross-reactive H9-binding antibodies, albeit at lower levels than against seasonal H3, with low to undetectable haemagglutination inhibition and neutralising antibodies.
Abstract
Understanding population immunity to emerging viruses is critical for risk assessment. We characterised antibody responses to avian influenza A(H9N2) viruses in 298 human sera from adults in New York City. We observed widespread cross-reactive H9-binding antibodies, albeit at lower levels (GMT = 371.3) than against seasonal H3 (GMT = 1,398.0), with low to undetectable haemagglutination inhibition and neutralising antibodies. In contrast, NA-binding and neuraminidase inhibition responses were moderate (GMT = 149.5 and 34.2) and comparable to those against human seasonal N2 (GMT = 259.0 and 42.2).
Citation format
SINGH, Gagandeep, et al. Cross-reactive human antibody responses to H9N2 influenza virus, new york, United States, 2025. Eurosurveillance, 2026, 31.