Persistence of H7N9 virus antibody response 2 years after infection.

We measured antibodies against H7N9 virus 2 years after infection in 14 patients who were infected during October 2016‐September 2017. Approximately 2 years after infection, antibody titers ≥10 were detectable in 13 (92.9%) patients. Three (21.4%) of 14 patients had hemagglutination inhibition titers ≥40, and their geometric mean titer (GMT) was 20 (95% CI 15.7‐28.1), whereas 10 (71.4%) and all 14 (100%) of the 14 patients had titers ≥40, and GMTs at 34.4 (95% CI 25.7‐51.2) and 73.45 (54.7‐106.7) for neuraminidase inhibition and microneutralization antibodies, respectively. Our findings suggest that H7N9 infection may induce long‐term antibody response at least 2 years after infection. [ABSTRACT FROM AUTHOR]